FAQ - Frequently Asked Questions | ACI Industriearmaturen GmbH
Frequently asked questions

FAQ - Frequently Asked Questions

On this page, our FAQ's - the answers to frequently asked questions are clearly listed in categories.

Of course, we will also be happy to answer your questions personally. Simply get in touch with us.

Fittings

Industrial fittings are mechanical control and regulating devices that influence the flow and pressure of fluids in a process. They mainly take place in pipelines and are available in a wide variety of designs. Among others, they include: Butterfly valves, globe valves and gate valves, ball and plug valves, sight glass fittings, pressure reducers, strainers and many more.

Some of these can act completely independently, while others are operated manually or automatically with an actuator. Each of these fittings has different functions and designs. Basically, however, most industrial fittings consist of a housing, an upper and inner part, as well as the actuation and the gasket.

The housing is the main element of a fitting. It holds all parts of a fitting together and absorbs the pressure loads of the incoming fluids. The housing is connected to the system via the connections, which can be threaded, flanged or welded.

The upper part is the cover for the housing opening and guides the spindle with the associated gaskets.

The internal parts are the shut-off element, valve seat, guides, screws, bushings, etc.. The shut-off element regulates or stops the flow depending on its position and comes in different geometries, such as a disc, cone or ball. The valve seat is the seating or sealing surface for the shut-off element. A fitting can have one or more seats.

The position of the shut-off element is adjusted by means of the actuation. Actuators can be, for example, levers, handwheels or also electric motors. The actuating element is connected to the shut-off element via the spindle, which transmits the actuating forces and torques.

A butterfly valve is a fitting that can be used to control and shut off the flow of various fluids such as liquids or gases in a pipeline. A rotating disc gradually regulates the flow until it is completely shut off. If the disc is parallel to the flow-direction, the fluid can flow almost without resistance. The step-by-step control is possible on the one hand manually with a crank or a lever and on the other hand automatically with an actuator. Butterfly valves are used in almost all industries where fluids have to be regulated.

Advantages:

  • Lightweight and space-saving
  • Universally applicable
  • Easily adaptable to a wide range of media

A "Double Block & Bleed" fitting is made of two shut-off fittings ("Double Block") with a fitting in between for emptying the space ("Bleed"). This type of fitting is usually used where the separation of two systems has to be particularly reliable. Whether the process media must not be allowed to mix, for maintenance work, to avoid contamination, etc., it is important to use a double block.

A ball valve is used to shut off pipes. The flow can be regulated via a drilled ball as a shut-off body. Depending on the size of the hole in the ball, a flow rate comparable to that in the pipe is possible. Compared to a plug valve, larger flow rates can be realised with a ball valve with full passage.

The plug valve is a fitting that is comparable to a ball valve. However, the plug valve does not have a spherical but a conical shut-off body. Like the ball valve, it is used to shut off pipes. The plug valve seals by pressing the contact surface against the housing. This means there is no gap between the shut-off body and the gasket where particles can penetrate or deposits can form. Plug valves are therefore particularly suitable for media containing solids.

Advantages:

  • Free of dead space in open and closed position
  • Long service life even with media containing solids

Sight glasses enable visual inspection of the inside of containers and pipelines as well as the determination of filling levels. These are roughly divided into tank sight glasses, flow sight glasses and level indicators.

Tank sight glasses consist of two flanges with a glass plate clamped in between. They are available in round design or as longitudinal sight glasses. Round tank sight glasses can be welded in or on or screwed to flange connections, for example. Longitudinal tank sight glasses, on the other hand, are usually welded in or on (cf. tank sight glasses).

Flow sight glasses consist of a housing and sight glasses attached to the side. Flow sight glasses can be connected via a flange connection, screwed via threads or welded in. As a special version of the flow sight glasses, the tubular flow sight glasses allow a 360° all-round view. They consist of a glass tube that is clamped between two flanges (cf. flow sight glasses).

Level indicators are attached to the outside of a container and indicate the level of the medium. Level indicators are divided into reflective indicators and glass tube level indicators (cf. level indicators). In the case of reflection indicators, an elongated sight glass plate is clamped between a housing and a cover frame. The medium penetrates through the connection openings so that the level can be read using the principle of communicating tubes. In the case of glass tube level indicators, a glass tube is fixed between two connection fittings, via which the level can be read.

Face-to-face lengths according to DIN EN 558-1 / -2 for intermediate flange fittings

INFO data sheet for face-to-face lengths acc. to DIN EN 558-1 / -2: DOWNLOAD


Flange fittings according to DIN EN 558-1 / 2 extract:

"Industrial valves - Face-to-face lengths of metal valves for installation in flanged pipelines - PN and Class designated valves"; German version EN 558:2017

table for face-to-face lengths according to DIN EN 558-1 / -2

Gasket materials

Aramid fibre gasket (KlingerSil® e.g. C-4400)


Product specification: Gasket 

Marterial: Aramid fibres, bonded with NBR (KlingerSil® e.g. C-4400), asbestos-free

colour: mostly green or yellow

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -100 to 175 °C / -148 to 347°F (higher and lower is possible depending on medium and application)

Operating pressure: up to 60 bar / 870 psi (higher is possible depending on medium and application)

Physical and chemical properties

Physical: Good ageing resistance, good pressure and temperature resistance

Chemical: Resistant to superheated steam and hot water, gases, salt solutions, fuels, alcohols, organic and inorganic acids, lubricants and coolants

EPDM gasket (elastomer)


Product specification: Gasket

Material: EPDM (Ethylene propylene diene monomer)

Colour: mostly black

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -50 to 130 °C / -58 to 266 °F (higher and lower is possible depending on the medium and area of application)

Operating pressure: up to16 bar / 232 psi (higher is possible up to 50 bar / 725 psi depending on medium and application)

Physical and chemical properties

Physical: Good ageing resistance, low to moderate pressure and temperature resistance

Chemical:

Resistant to water, glycols and brake fluids (glycol-based), acids (hydrochloric acid, nitric acid), alkalis (sodium hydroxide solution, potassium hydroxide solution), polar organic solvents (e.g. acetic acid), oxidising media (e.g. peracetic acid).

Not resistant to mineral greases, oils and waxes, fuels (petrol, diesel, etc.)

FFKM-Gasket (elastomer)


Product specification: Gasket

Material: FFKM (Perfluoro rubber)

Colour: mostly black

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -25 to 325 °C / -13 to 617 °F (depending on the medium and application, higher and lower values are possible)

Long-term temperature resistance:: up to 260 °C / 500 °F

Operating pressure: up to 16 bar / 232 psi (higher is possible up to 170 bar / 2465 psi depending on medium and application)

Physical and chemical properties

Physical: Very good ageing resistance, highest pressure and temperature resistance among elastomers, vacuum compatible

Chemical:

Resistant to mineral oils, greases and waxes, engine oils, fuels, aliphatic and aromatic hydrocarbons, amines, hydraulic fluids, essential oils, moderate and low concentrated acids.

Not resistant to conc. acids (e.g. nitric acid, formic acid), conc. oxidising media (e.g.: peracetic acid).

FKM-gasket (elastomer)


Product specification: Gasket

Material: FKM (fluororubber)

Colour: mostly black

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -20 to 230 °C / -4 to 446 °F (depending on the medium and application, higher and lower values are possible)

Long-term temperature resistance: up to 200°C / 392 °F

Operating pressure: up to 16 bar / 232 psi (higher is possible up to 90 bar / 1305 psi depending on medium and application)

Physical and chemical properties

Physical: Very good ageing resistance, high pressure and temperature resistance under elastomers, vacuum compatible

Chemical:

Resistant to mineral oils, greases and waxes, engine oils, fuels, aliphatic and aromatic hydrocarbons, amines, hydraulic fluids, essential oils, moderate and low concentrated acids.

Not resistant to conc. acids (e.g. nitric acid, formic acid), conc. oxidising media (e.g.: peracetic acid).

Graphite composite gasket (Frenzelit e.g. novaphit® MST / XP)


Product specification: Gasket

Material: expanded graphite with internal impregnation and plain and expanded metal inserts

Colour: grey, silver

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -200 to 500 °C / -328 to 932 °F (depending on medium and application)

Operating pressure: up to 250 bar / 3625 psi (higher is possible depending on medium and application)

Physical and chemical properties

PhysicalVery good ageing resistance, very high pressure and temperature resistance.

Chemical: Very good universal resistance to superheated steam and hot water, gases, salt solutions, fuels, alcohols, organic and inorganic acids, lubricants, coolants, alkalis, greases, etc.

Pure graphite gasket (Frenzelit e.g. novaphit® VS)


Product specification: Gasket

Material: Expanded graphite without plain and expanded metal inserts

Colour: grey, silver

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -200 to 500 °C / -328 to 932 °F (depending on medium and application)

Operating pressure: up to 60 bar / 870 psi (higher is possible depending on medium and application)

Physical and chemical properties

PhysicalVery good ageing resistance, very high pressure and temperature resistance.

Chemical: Very good universal resistance to superheated steam and hot water, gases, salt solutions, fuels, alcohols, organic and inorganic acids, lubricants, coolants, alkalis, greases, etc.

NBR gasket (elastomer)


Product specification: Gasket

Material: NBR (acrylonitrile butadiene rubber)

Colour: mostly black

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -30 to 100 °C / -22 to 212 °F (higher and lower is possible depending on the medium and area of application)

Operating pressure: up to 16 bar / 232 psi (higher is possible up to 50 bar / 725 psi depending on medium and application)

Physical and chemical properties

Physical: Sufficient ageing resistance, low to moderate pressure and temperature resistance

Chemical:

Resistant to mineral oils, greases and waxes (i.e. also engine oils), fuels (petrol, diesel, etc.).

Not resistant to conc. acids (e.g. nitric acid, formic acid), conc. oxidising media (e.g. peracetic acid), aromatic and chlorinated hydrocarbons

Phlogopite mica gasket (Frenzelite e.g. novamica® THERMEX)


Product specification: Gasket

Material: Phlogopite mica with expanded metal inlays

Colour: brownish, golden

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -200 to 1000 °C / -328 to 1832 °F (depending on medium and application)

Operating pressure: up to 60 bar / 870 psi (higher is possible depending on medium and application)

Physical and chemical properties

Physical: Good ageing resistance, maximum temperature resistance at high pressures

Chemical: Very good chemical resistance, excellent for exhaust gases from kilns or similar.

PTFE gasket (polytetrafluoroethylene)


Product specification: Gasket

Material: Polytetrafluoroethylene(PTFE)

Colour: white

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties:

Operating temperature: -100 to 250 °C / -148 to 482°F (depending on medium and application)

Long-term temperature resistance: up to 200°C / 392°F

Melting point: 327°C / 620.6°F

Betriebsdruck: up to 100 bar / 1450 psi (depending on medium and application)

Physical and chemical properties

Physical: Very good ageing resistance, good pressure and temperature resistance

Chemical: Almost universally resistant, Not usable with alkali metals, elemental fluorine and chlorine trifluoride at high pressures

Silicone-gasket (elastomer)


Product specification: Gasket

Material: Silicone (vinyl methyl silicone rubber)

Colour: mostly grey to white

INFO Data sheet to all gasket types: DOWNLOAD

Technical properties

Operating temperature: -60 to 180 °C / -76 to 356 °F (higher and lower is possible depending on the medium and area of application)

Operating pressure: bis 16 bar / 232 psi (higher is possible up to 20 bar / 290 psi depending on medium and application)

Physical and chemical properties

Physical: Medium ageing resistance, low to moderate pressure and temperature resistance

Chemical:

Resistant to mineral oils, greases and waxes and motor oils, animal and vegetable fats, essential oils.

Not resistant to conc. acids (e.g. nitric acid, formic acid); conc. oxidising media (e.g. peracetic acid); esters and ethers; aromatic hydrocarbons.

Pressure Equipment Directive (PED 2014/68/EU)

„good engineering practice“ means that this pressure equipment has been designed taking into account all relevant factors affecting its safety. In addition, the equipment is so manufactured, inspected and supplied with instructions for use that, when used under foreseeable or reasonably foreseeable conditions, its safety is assured during its intended life.

The manufacturer is responsible for compliance with good engineering practice.

When placing on the market pressure equipment or assemblies of several pressure equipment connected by a manufacturer to form a coherent functional unit , covered by Article 4 (3) (good engineering practice), what information should be supplied to indicate that it complies with the provisions of Article 4 (3)?

There is no specific provision in the Directive on how the manufacturer must indicate that this equipment is in conformity with the PED.

However, the manufacturer must include sufficient instructions for use and affix a marking enabling the manufacturer or his authorised representative established within the Community to be identified.
Manufacturers should be aware that it is likely to be helpful if they accompany the product with a reference to the PED indicating that the requirements of good engineering practice in force in a Member State have been met.

This can be realised, for example, by a statement included in the operating instructions or by a separate document attached to the equipment or by an addition to the marking.

INFO Data sheet - Good engineering practice: DOWNLOAD

Technical documentation

The documentation prepared by the manufacturer shall enable the conformity of the pressure equipment with the applicable requirements to be assessed and shall include an appropriate risk analysis and assessment. The technical documentation shall specify the applicable requirements and, as far as necessary for the assessment, cover the design, manufacture and operation of the pressure equipment. The technical documentation shall include at least the following elements, as appropriate:

  • a general descriptionof the pressure equipment,
  • conceptual design and manufacturing drawings and diagrams of components, sub-assemblies, circuits,etc.,
  • descriptions and explanations necessary for an understanding of those drawings and diagrams and the operation of the pressure equipment,
  • a list of which harmonized standards have been applied in full or in part and a description of the solutions adopted to meet the essential safety requirements of this Directive where those harmonized standards have not been applied; in the case of partially applied harmonized standards, those parts shall be indicated in the technical file,
  • results of design calculations made, examinations carried out, etc.,
  • test reports.

Manufacturing

The manufacturer shall take all measures necessary so that the manufacturing process and its monitoring ensure compliance of the manufactured pressure equipment with the technical documentation and with the requirements of the relevant directive.

CE marking and EU declaration of conformity:

  • The manufacturer shall affix the CE marking to each item of pressure equipment that satisfies the applicable requirements of the relevant directive.
  • The manufacturer shall draw up a written EU declaration of conformity for one model of the pressure equipment and keep it together with the technical documentation at the disposal of the national authorities for 10 years after the pressure equipment has been placed on the market. The EU declaration of conformity must clearly identify the pressure equipment for which it was issued.

Data sheet: DOWNLOAD

Technical documentation

The documentation prepared by the manufacturer shall enable the conformity of the pressure equipment with the applicable requirements to be assessed and shall include an appropriate risk analysis and assessment. The technical documentation shall specify the applicable requirements and, as far as necessary for the assessment, cover the design, manufacture and operation of the pressure equipment. The technical documentation shall include at least the following elements, as appropriate:

  • a general descriptionof the pressure equipment,
  • conceptual design and manufacturing drawings and diagrams of components, sub-assemblies, circuits,etc.,
  • descriptions and explanations necessary for an understanding of those drawings and diagrams and the operation of the pressure equipment,
  • a list of which harmonized standards have been applied in full or in part and a description of the solutions adopted to meet the essential safety requirements of this Directive where those harmonized standards have not been applied; in the case of partially applied harmonized standards, those parts shall be indicated in the technical file,
  • results of design calculations made, examinations carried out, etc.,
  • test reports.

Manufacturing

The manufacturer shall take all measures necessary so that the manufacturing process and its monitoring ensure compliance of the manufactured pressure equipment with the technical documentation and with the requirements of this Directive.

Final assessment and pressure equipment checks:

The manufacturer shall perform a final assessment of the pressure equipment, which is monitored in the form of unannounced visits by the manufacturer‘s selected notified body.
The notified body carries out product tests or has them carried out at irregular intervals determined by it in order to check the quality of the internal pressure equipment tests. In doing so, it takes into account, among other things, the technical complexity of the pressure equipment and the production volume.

During these visits, the notified body shall:

  • make sure that the manufacturer actually carries out the final assessment according to Annex I point 3.2 of the PED;
  • take samples of pressure equipment in the manufacturing or storage facilities for inspection purposes. The notified body shall decide on the number and, if necessary, whether to carry out or have carried out all or part of the final assessment test.

The purpose of this sampling procedure is to determine if the manufacturing process of the pressure equipment is within acceptable limits to ensure the conformity of the pressure equipment.
In case of non-conformity of one or more pressure equipment, the notified body shall take appropriate measures.

The manufacturer shall, under the responsibility of the notified body, affix its identification number during the manufacturing process.

CE marking and EU declaration of conformity:

  • The manufacturer shall affix the CE marking to each item of pressure equipment that satisfies the applicable requirements of this Directive.
  • The manufacturer shall draw up a written EU declaration of conformity for one model of the pressure equipment and keep it together with the technical documentation at the disposal of the national authorities for 10 years after the pressure equipment has been placed on the market. The EU declaration of conformity must clearly identify the pressure equipment for which it was issued.

A copy of the EU declaration of conformity shall be made available to the competent authorities upon request.

The EU declaration of conformity must contain the following information:

  1. Pressure equipment or assembly (product, type, batch or serial number):
  2. Name and address of the manufacturer and, where applicable, his authorisedrepresentative:
  3. This declaration of conformity is issued under the sole responsibility of themanufacturer.
  4. Object of the declaration (identification of pressure equipment or assembly allowingtraceability; it may, where necessary for the identification of the pressureequipment or assembly, include an image):
    1. description of the pressure equipment or assembly,
    2. conformity assessment procedure followed,
    3. in the case of assemblies, description of the pressure equipment constituting the assembly,and the conformity assessment procedures followed,
  5. The object of the declaration described above is in conformity with the relevantUnion harmonisation legislation:
  6. References to the relevant harmonised standards used or references to the other technicalspecifications in relation to which conformity is declared:
  7. Where appropriate, the name, address and number of the notified body which carriedout the conformity assessment and the number of the certificate issued ,and a reference to the EU-type examination certificate – production type, EU- type examination certificate – design type, EU design examinationcertificate or certificate of conformity.
  8. Additionalinformation:
  • Signed for and on behalf of:
  • (place and date of issue):
  • (name, function) (signature):
  • (where appropriate, particulars of the signatory authorised to sign thelegally binding declaration for the manufacturer or his authorised representative)

Data sheet: DOWNLOAD

      Manufacturing

      The manufacturer shall operate an approved quality system for design, manufacture, final product inspection and testing of the pressure equipment and shall be subject to surveillance by a notified body..

      Quality system

      The manufacturer must apply to a notified body of his choice for the assessment of his quality system for the pressure equipment concerned. The application should include the following:

      • Name and address of the manufacturer (and of the authorized representative, if necessary)
      • the technical documentation for a model of each type of pressure equipment to be manufactured:
        • ageneral description of the pressure equipment,
        • conceptualdesign and manufacturing drawings and diagrams of components, sub-assemblies,circuits, etc.,
        • descriptionsand explanations necessary for the understanding of those drawings anddiagrams and the operation of the pressure equipment,
        • a list of the harmonised standards the references of which have been publishedin the Official Journal of the European Union, applied in full or in part,and descriptions of the solutions adopted to meet the essential safetyrequirements of this Directive where those harmonised standards have notbeen applied. In the event of partly applied harmonised standards, thetechnical documentation shall specify the parts which have been applied,
        • resultsof design calculations made, examinations carried out, etc.,
      • testreports,
      • the documentationconcerning the quality system, and
      • a written declarationthat the same application has not been lodged with any other notifiedbody.

      The quality system shall ensure compliance of the pressure equipment with the requirements of the relevant directive that apply to it. The manufacturer shall ensure that the elements, requirements and provisions adopted are systematic and orderly. This shall ensure a consistent interpretation of the quality programs, plans, manuals and records.

      In particular, they must contain an adequate description of:

      • Quality objectives and organizational structure, responsibilities and authority of management with respect to design and product quality;
      • technical design specifications, including the applied standards;
      • Techniques for controlling the development and testing the development result, procedures and systematic measures used in the development of the pressure equipment belonging to the product category in question;
      • the corresponding manufacturing, quality control and quality assurance techniques, processes and systematic actions that will be used, in particular the approved working procedures that will be used to produce the permanent joints
      • examinations and tests carried out before, during and after manufacture, specifying their frequency;
      • the quality-related records, e.g. test reports, qualification or approval of involved employees, etc.
      • Means of monitoring the achievement of the required development and pressure equipment quality and the effective operation of the quality system.

      The notified body shall assess the quality system to determine whether the above requirements have been met.

      In addition to experience with quality management systems, at least one member of the audit team shall have experience as an assessor in the relevant pressure equipment field and pressure equipment technology concerned, as well as knowledge of the applicable requirements of the directive concerned. The audit shall also include an inspection visit to the manufacturer‘s premises. The auditing team shall review the technical documentation to verify the manufacturer‘s ability to identify the applicable requirements of the directive concerned and to carry out the necessary examinations with a view to ensuring compliance of the pressure equipment with those requirements.

      The manufacturer shall undertake to fulfil the obligations arising out of the approved quality system and to uphold it so that it remains adequate and efficient.
      The manufacturer shall keep the notified body informed of any intended change of the quality system. The notified body shall evaluate the modifications proposed and decide whether the modified quality system will still satisfy the requirements referred to above or whether a reassessment is required.

      Surveillance under the responsibility of the notified body

      The purpose of surveillance is to make sure that the manufacturer duly fulfils the obligations arising out of the approved quality system.
      The manufacturer shall, for assessment purposes, allow the notified body access to the locations of design, manufacture, inspection, testing and storage, and shall provide it with all necessary information, in particular

      • the documentation on the quality assurance system;
      • quality-related records intended for the development area, such as results of analyses, calculations or tests;
      • quality-related records intended for the manufacturing area, for example, inspection reports, test data, or reports on the qualifications of the employees working in this area.

      The notified body shall periodically carry out audits to ensure that the manufacturer maintains and applies the quality system.

      In addition, the notified body may pay unannounced visits to the manufacturer, taking into account in particular the following factors:

      • Category of the pressure equipment;
      • Results of previous monitoring visits;
      • required tracking of corrective actions;
      • any special conditions attached to the approval of the system;
      • significant changes in manufacturing organization, manufacturing concepts, or manufacturing techniques.

      During such visits, the notified body may, if necessary, carry out product tests, or have them carried out, to verify that the quality system is functioning correctly.

      CE marking and EU declaration of conformity:

      The manufacturer shall affix the CE marking and, under the responsibility of the notified body referred to above, the latter‘s identification number to each item of pressure equipment where required by the Directive.
      In addition, a written EU declaration of conformity shall be issued for one model of the pressure equipment and kept at the disposal of the national authorities for ten years after the pressure equipment has been placed on the market, together with the technical documentation. The EU declaration of conformity must clearly identify the pressure equipment for which it was issued.
      A copy of the EU declaration of conformity shall be made available to the competent authorities upon request.

      The documents to be kept available by the manufacturer are in particular:

      • technical documentation
      • quality assurance system documentation
      • approved modifications
      • decisions and reports of the notified body

      The EU declaration of conformity must contain the following information:

      1. Pressure equipment or assembly (product, type, batch or serial number):
      2. Name and address of the manufacturer and, where applicable, his authorisedrepresentative:
      3. This declaration of conformity is issued under the sole responsibility of themanufacturer.
      4. Object of the declaration (identification of pressure equipment or assembly allowingtraceability; it may, where necessary for the identification of the pressureequipment or assembly, include an image):
        1. description of the pressure equipment or assembly,
        2. conformity assessment procedure followed,
        3. in the case of assemblies, description of the pressure equipment constituting the assembly,and the conformity assessment procedures followed,
      5. The object of the declaration described above is in conformity with the relevantUnion harmonisation legislation:
      6. References to the relevant harmonised standards used or references to the other technicalspecifications in relation to which conformity is declared:
      7. Where appropriate, the name, address and number of the notified body which carriedout the conformity assessment and the number of the certificate issued ,and a reference to the EU-type examination certificate – production type, EU- type examination certificate – design type, EU design examinationcertificate or certificate of conformity.
      8. Additionalinformation:
      • Signed for and on behalf of:
      • (place and date of issue):
      • (name, function) (signature):
      • (where appropriate, particulars of the signatory authorised to sign thelegally binding declaration for the manufacturer or his authorised representative)

      Data sheet: DOWNLOAD

      Fastening technology / Bolting

      Austenitic stainless steels play a major role in fastening technology / screw connections. The fastening elements used in our products are selected at least in steel grade A4. What these and other abbreviations mean is explained in more detail below.

      Abbreviations and classification of austenitic stainless steels

      Example: "A4-70"

      A

      4

      70

      Abbreviation of the steel group:
      A = austenitic stainless steel
      Abbreviation of the steel grade:
      1 = Free cutting steel

      2 = Cold heading steel alloyed with chromium and nickel

      3 = Cold heading steel alloyed with chromium and nickel and hardened with tantalum, niobium and titanium

      4 = Cold heading steel alloyed with chromium, molybdenum and nickel

      5 = Cold heading steel alloyed with chromium, molybdenum and nickel and hardened with tantalum, niobium and titanium
      Indication of the tensile strength:
      50 = 1/10 of the tensile strength (min. 500 N/mm²)

      70 = 1/10 of the tensile strength (min. 700 N/mm²)

      80 = 1/10 of the tensile strength (min. 800 N/mm²)
      Steel group / steel grade Material number
      A1 1.4300
      1.4305
      A2 1.4301
      1.4303
      1.4306
      A3 1.4306
      1.4550
      1.4590
      A4 1.4401
      1.4404
      1.4306
      A5 1.4436
      1.4571
      1.4580

      Steel grade A1 is particularly easy to machine due to its high sulphur content, but has a lower corrosion resistance than the other steels.

      Grade A2 is the most commonly used. However, they are not suitable for applications with non-oxidising acid or chloride-containing media.

      A3 steels have the same properties as A2 steels, but they are stabilised with titanium, niobium or tantalum. This improves corrosion resistance at high temperatures.

      A4 steels have the same properties as A2 steels. They are alloyed with molybdenum, which significantly improves corrosion and acid resistance.

      A5 steels have the same properties as A4 steels. They are stabilised with titanium, niobium or tantalum, which makes them resistant to high temperatures.

      INFO data sheet fasteners made of austenitic stainless steel: DOWNLOAD

      Marking of bolting elements

      Example of a hexagon head screw DIN 933 made of A4-70

      Example of a cylinder head cap screw with hexagon socket ISO 4762 (replaces DIN 912) made of A4-70

      Example of a hexagon nut DIN 934 made of A4-70

      INFO Data sheet marking of bolting elements: DOWNLOAD

      Example drawing for the marking of fasteners
      Tabelle Withworth Rohrgewinde Arten in der Übersicht

      The following thread types can be connected as follows according to the table above:

      INFO Data sheet Withworth raw thread: DOWNLOAD

      Glass materials

      Borosilicate glass according to and following DIN 7080

      Product specification: Round sight glass plates

      Material: Borosilicate glass thermally toughened (hardened)

      Removal rates and further information on the glass can be found in our info data sheet and in our brochure.

      INFO Data Sheet Round Sight Glass Plates acc. to and following DIN 7080 DOWNLOAD

      MAXOS® Brochure: DOWNLOAD

      MAXOS® borosilicate glass safety sight glasses are required wherever visual inspection of processes in containers must be ensured under pressure, thermal and chemical stress.

      The high level of safety is achieved by using a special borosilicate glass with good chemical resistance, extraordinary purity and homogeneity. In combination with the low thermal expansion typical of this borosilicate glass, thermal tempering (hardening) leads to a particularly high thermal shock resistance.

      Production and quality checks in the process sequence guarantee the property values of the glasses and the close dimensional tolerances. With these outstanding safety properties, MAXOS® safety sight glasses can be used for extreme conditions.

      Operating conditions:

      Temperature:

      • 280 °C / 536 °F long-term
      • 300 °C / 572 °F short-term (<300 h)
      • 320 °C / 608 °F with mica protected

      Pressure: depending on diameter and thickness

      Calculation of the pressure resistance:: TOOL - Glass consultant borosilicate glass DIN 7080

      Technical informations:

      Coefficient of expansion at 20 °C / 300 °C (68 °F / 572 °F) : 4.1 x 10–6 K–¹

      Young's modulus: 67 x 103 N/mm²

      Thermal conductivity at 90 °C / 194 °F: 1.2 W/(m·K)

      Stress-optical coefficient K: 3.2 x 10–6 mm²/N

      Thermal shock resistance: 265 °C / 509 °F

      Chemical resistance:

      Water resistance DIN ISO 719/720: Hydrolysis class 1

      Acid resistance DIN 12116: Acid class 1

      Alkali resistance DIN 52332: Alkali class 2

      Permissible material defects:

      Round bubbles enclosed in the glass may have a maximum diameter of 2 mm. Oval bubbles must not exceed the value (length + width)/2 = 2 mm. Pointed bubbles are not permitted.

      Permissible bubble frequency

      Bubble diameter d3  | Permissible bubble frequency
      d3 < 0,3 3 pieces per cm² visible surface
      0,3 ≤ d3 ≤ 0,5 10 pieces per sight glass plate
      0,5 < d3 ≤ 1 4 pieces per sight glass plate
      1 < d3 ≤ 2 2 pieces per sight glass plate

      Dimensional tolerances:

      The dimensional tolerances are in accordance with DIN 7080 for sightglass plates made of borosilicate glass.

      Dimensional tolerances according to DIN 7080

      Diameter | tolerance
      up to 135 mm ± 0,5 mm
      150 to 200 mm ± 0,8 mm
      over 200 mm ± 1,0 mm
      Thickness
      up to 20 mm + 0,50 mm / – 0,25 mm
      over 20 mm + 0,80 mm / – 0,40 mm

      Borosilicate glass according to and following DIN 7081

      Product specification: Long sight glass panels

      Material: Borosilicate glass thermally toughened (hardened)

      Removal rates and further information on the glass can be found in our info data sheet and in our brochure.

      INFO Data Sheet Round Sight Glass Plates according to and i.A. DIN 7081: DOWNLOAD

      MAXOS® Brochure: DOWNLOAD

      MAXOS® borosilicate glass safety sight glasses are required wherever visual inspection of processes in containers must be ensured under pressure, thermal and chemical stress.

      The high level of safety is achieved by using a special borosilicate glass with good chemical resistance, extraordinary purity and homogeneity. In combination with the low thermal expansion typical of this borosilicate glass, thermal tempering (hardening) leads to a particularly high thermal shock resistance.

      Production and quality checks in the process sequence guarantee the property values of the glasses and the close dimensional tolerances. With these outstanding safety properties, MAXOS® safety sight glasses can be used for extreme conditions.

      Operating conditions:

      The pressure-temperature assignment in the INFO data sheet must be observed! The following table is for orientation purposes only.

      Calculation of the pressure resistance: TOOL - Glass consultant borosilicate glass DIN 7081

      Operating method: Max. operating 
      pressure:
      Max. operating 
      temperature:
      Unprotected reflex and transparent sight glasses 
      with saturated steam or hot water pressure
      35 bar / 
      500 psi
      243 °C / 
      470 °F
      Mica-protected transparent sight glasses 
      with saturated steam or hot water pressure
      103 bar / 
      1500 psi
      320 °C / 
      608 °F
      Reflex sight glasses when used without steam 
      and without technically significant glass attack
      280 bar / 
      4000 psi
      38 °C / 
      100 °F
      For media without technically significant glass 
      attack for transparent sight glasses
      345 bar / 
      5000 psi
      38 °C / 
      100 °F
      High-pressure transparent sight glasses 
      in special fittings
      414 bar / 
      6000 psi
      38 °C / 
      100 °F

      Chemical resistance:

      Water resistance DIN ISO 719/720: Hydrolysis class 1

      Acid resistance DIN 12116: Acid class 1

      Alkali resistance DIN 52332: Alkali class 2

      Technical information:

      Coefficient of expansion at 20 °C / 300 °C (68 °F / 572 °F) : 4.1 x 10–6 K–¹

      Young's modulus: 67 x 103 N/mm²

      Thermal conductivity at 90 °C / 194 °F: 1.2 W/(m·K)

      Stress-optical coefficient K: 3.2 x 10–6 mm²/N

      Thermal shock resistance: 265 °C / 509 °F

      Permissible material defects:

      Round bubbles enclosed in the glass may have a maximum diameter of 2 mm. Oval bubbles must not exceed the value (length + width)/2 = 2 mm. Pointed bubbles are not permitted.

      Permissible bubble frequency

      bubble diameter. (d3) Permissible bubble frequency
      Permissible bubble frequency
      ≤ 250 mm > 250 mm
      d3 < 0,3 3 pieces per cm² visible surface 3 pieces per cm² visible surface
      0,3 ≤ d3 ≤ 0,5 10 pieces per glass 15 pieces per glass
      0,5 < d3 ≤ 1 4 pieces per glass 6 pieces per glass
      1 < d3 ≤ 2 2 pieces per glass 3 pieces per glass

      Dimensional tolerances:

      The dimensional tolerances are in accordance with DIN 7081 for borosilicate glass sight glasses. The parallelism is ≤ 0.08 mm for standard sight glasses and ≤ 0.05 mm for high-pressure sight glasses.

      Dimensional tolerances according to DIN 7081

      Dimensional tolerances for longitudinal glass width 34 mm:

      Tolerance
      Length (95 ... 400 mm) + 0 mm / – 1,5 mm
      Wide (34 mm) + 0,2 mm / – 0,8 mm
      Thickness(17,5 mm) + 0 mm / – 1,0 mm

      Dimensional tolerances for longitudinal glass width 30 mm:

      Length(115 ... 340 mm) Tolerance
      up to 250 mm ± 0,8 mm
      over 250 mm ± 1,0 mm
      Wide (30 mm) + 0,5 mm / – 0,8 mm
      Thickness(17,5 mm) + 0 mm / – 1,0 mm

      Soda-lime glass according to and following DIN 8902


      Product specification: Round sight glass panels

      Material: Soda-lime glass


      You will find removal rates and further information on the glass in our info data sheet

      INFO Data sheet Round sightglass panels according to and in accordance with DIN 8902: DOWNLOAD

      Soda-lime glasses are required wherever visual inspection of processes in containers must be ensured under pressure, at low thermal and chemical stress.

      Operating conditions:

      Temperature: 150°C / 302 °F long-term

      Pressure: depending on diameter and thickness

      Calculation of the pressure resistance: TOOL - Glass consultant soda-lime glass

      Technical information:

      Coefficient of expansion at 20 °C / 300 °C (68 °F / 572 °F) : 9,5 x 10–6 K–¹

      Thermal shock resistance: 150 °C / 302 °F

      Chemical resistance:

      Water resistance DIN ISO 719/720: Hydrolysis class 1

      Acid resistance DIN 12116: Acid class 1

      Alkali resistance DIN 52332: Alkali class 2

      Permissible material defects:

      Round bubbles enclosed in the glass may have a maximum diameter of 2 mm. Oval bubbles must not exceed the value (length + width)/2 = 2 mm. Pointed bubbles are not permitted.

      Permissible bubble frequency

      Bubble diameter d3  Permissible bubble frequency
      d3 < 0,3 3 pieces per cm² visible surface
      0,3 ≤ d3 ≤ 0,5 10 pieces per sight glass plate
      0,5 < d3 ≤ 1 4 pieces per sight glass plate
      1 < d3 ≤ 2 2 pieces per sight glass plate



      Dimensional tolerances:

      The dimensional tolerances are in accordance with DIN 8902 for sightglass panels made of soda-lime glass.

      Dimensional tolerances according to DIN 8902

      Diameter  Tolerance
      up to 125 mm ± 0,5 mm
      125 to 200 mm ± 0,8 mm
      over 200 mm ± 1,0 mm
      Thickness
      10 to 20 mm ± 0,50 mm
      over 20 mm ± 0,80 mm

      BOROFLOAT® sight glass plates

      Product specification: Round sight glass plates, longitudinal sight glass plates

      Material: BOROFLOAT® 33

      You will find removal rates and further information on the glass in our info data sheet.

      INFO Data sheet Round sight glass plates made of BOROFLOAT®: DOWNLOAD

      BOROFLOAT® sight glasses are required wherever visual inspection of processes in vessels under pressure, thermal and chemical stress must be ensured.

      Due to the very low coefficient of expansion common to BOROFLOAT® 33, it is characterised by high temperature resistance. In addition, it has excellent thermal shock resistance. BOROFLOAT® glass sheets are not thermally toughened (not hardened) and therefore offer significantly higher temperature application conditions.

      Production and quality checks in the process sequence guarantee the property values of the glasses and the tight dimensional tolerances. With these excellent temperature properties, BOROFLOAT® sight glasses can be used for extreme conditions.

      Operating conditions:

      Temperature:

      • 450 °C / 842 °F long-term
      • 500 °C / 932 °F short-term (< 10 h)

      Pressure: depending on diameter and thickness

      Calculation of the pressure resistance: TOOL - Glass consultant Borofloat glass

      Technical information:

      Coefficient of expansion at 20 °C / 300 °C (68 °F / 572 °F) : 3,25 x 10–6 K–¹

      Young's modulus: 64 kN/mm²

      Thermal conductivity at 90 °C / 194 °F:1.2 W/(m·K)

      Stress-optical coefficient K: 4,0 x 10–6 mm²/N-¹

      Thermal shock resistance: 133 °C / 271,4 °F

      Chemical resistance:

      Water resistance DIN ISO 719/720: Hydrolysis class 1

      Acid resistance DIN 12116: Acid class 1

      Alkali resistance DIN 52332: Alkali class 2

      Synthetic quartz glass

      Product specification: Round sight glass plates, longitudinal sight glass plates, sight glass rings / tubes

      Material: synthetic quartz glass

      Optical properties as well as further information on the glass can be found in our info data sheet

      INFO Data sheet synthetic quartz glass: DOWNLOAD

      Flame-fused synthetic fused silica sight glasses are required wherever visual inspection of processes in vessels must be ensured under extreme pressure, at very high thermal and chemical stress.

      Synthetic fused silica is ≥99.9995% SiO2, making it ideal for precision optics, lasers, lithography and electronics. It has superior chemical resistance and is ideal for high temperature applications.

      Production and quality checks in the process sequence guarantee the property values of the glasses and the tight dimensional tolerances. With these outstanding properties, these sight glasses are suitable for extreme conditions.

      Operating conditions:

      Temperature:

      • 1000 °C / 1832 °F long-term
      • 1200 °C / 2192 °F short-term

      Pressure: depending on diameter and thickness

      Calculation of the pressure resistance: TOOL - Glass consultant quartz glass

      Technical information

      Coefficient of expansion at 20 °C / 300 °C (68 °F / 572 °F) : 5,4 x 10–7 cm °C

      Young's modulus: 7,2 x 10^10 Pa

      Thermal conductivity at 90 °C / 194 °F: 1,4 W/(m·°C)

      Thermal shock reistance: 220 °C / 428 °F

      Chemical resistance:

      Water resistance DIN ISO 719/720: Hydrolysis class 1

      Acid resistance DIN 12116: Acid class 1

      Alkali resistance DIN 52332: Alkali class 1


      Sapphire glass

      Product specifications: Round sight glass plates, longitudinal sight glass plates, sight glass rings / tubes

      Material: Sapphire monocrystal

      Optical properties as well as further information on the glass can be found in our info data sheet

      INFO Data sheet sapphire glass: DOWNLOAD

      Sapphire monocrystal sight glasses are required wherever visual inspection of processes in containers must be ensured under extreme pressure, thermal and chemical stress.

      Sapphire glass consists of 99.997% Al2O3 and is therefore very suitable for transmission in the UV range. It is characterised by above-average chemical resistance. In addition, it is the best choice for extreme high-temperature applications.

      Production and quality checks in the process sequence guarantee the property values of the glasses and the tight dimensional tolerances. With these outstanding properties, these sight glasses are suitable for extreme conditions.

      Operating conditions:

      Temperature: up to 2000 °C / 3632 °F

      Pressure: depending on diameter and thickness

      Calculation of the pressure resistance: TOOL - Glass consultant sapphire glass

      Technical information:

      Coefficient of expansion at 25 °C / 50 °C (77°F / 122°F) :6,6 x 10–6 cm °C-1

      Young's modulus: E 4,6 * 10² GNm

      Thermal conductivity at 25 °C / 77 °F: 0,08 cal cm-1 s-1 °C-1

      Chemical resistance:

      Water resistance DIN ISO 719/720: Hydrolysis class 1

      Acid resistance DIN 12116: Acid class 1

      Alkali resistance DIN 52332: Alkali class 1

      Quality:

      Sapphire glass offers very different qualities. These are, due to the cultivation of the sapphire crystals, completely arbitrary and are determined after testing. Synthetic sapphire glass is evaluated to be suitable for the intended application. Either optically, mechanically, etc. A very high quality sapphire galss produces little or no light scattering or grating distortion and is mainly used for the most demanding optical applications.

      Lower quality sapphire glasses can have high light scattering or grating distortion and are therefore mainly used for mechanical, structural applications and less demanding optical applications. Nevertheless, for all qualities, sapphire glass is very high quality compared to other materials, such as borosilicate glass.

      Tubes and capillaries made of borosilicate glass 3.3

      Product specifications: Tubes and capillaries 

      Material: Borosilicate glass 3.3

      You can find more information about the glass in our info data sheet.

      INFO Data sheet Borosilicate glass 3.3 tubes and capillaries: DOWNLOAD

      Borosilicate tube 3.3 is required wherever visual inspection of processes in pipelines must be guaranteed under pressure, thermal and chemical stress.

      The high level of safety is achieved by using a special borosilicate glass with good chemical resistance, exceptional purity and homogeneity. The low thermal expansion typical of this borosilicate glass results in a particularly high thermal shock resistance.

      Production and quality checks in the process sequence guarantee the property values of the glasses and the tight dimensional tolerances. Tensile, compressive and torsional forces must be avoided under all circumstances.

      Operating conditions:

      Temperature: 300 °C / 572 °F

      Pressure: depending on diameter and thickness

      Calculation of the pressure resistance: TOOL - Glass consultant borosilicate glass tubes

      Technical information:

      Coefficient of expansion at 20 °C / 300 °C (68 °F / 572 °F): 3.3 x 10–6 K–¹

      Young's modulus: 64 x 10³ N/mm²

      Thermal conductivity at 20 to 100 °C: 1.2 W/(m·K)

      Stress-optical coefficient K: 4.0 x 10–6 mm²/N

      Thermal shock resistance: 303 ... 115 °C (depending on the wall thickness of the pipe)

      Chemical resistance:

      Water resistance DIN ISO 719/720: Hydrolysis class 1

      Acid resistance DIN 12116: Acid class 1

      Alkali resistance DIN 52332: Alkali class 2


      Protective glass discs

      Mica protective discs

      Product specification: protective disc

      Material: Muscovite natural mica, phlogopite natural mica

      Mica quality grades, sizes and more information can be found in our info datasheet.

      INFO Data Sheet Mica / Mica Protective Discs: DOWNLOAD

      Original ACI mica discs can be used if the sight glass plates, for example made of borosilicate glass, are exposed to strong chemical stress.

      Our mica discs are made of muscovite natural mica (clear quality) and have virtually no influence on the visibility of transparent sight glasses. Furthermore, mica discs increase the temperature resistance and service life of borosilicate sight glasses, for example.

      Production and quality checks during the process guarantee the property values of the mica discs and the close dimensional tolerances. With these outstanding properties, mica discs can be used as an additional safety design, to sight glass plates, under extreme conditions.

      Operating conditions:

      Muscovit mica Phlogopit mica
      Long-term thermal resistance: 500 °C 700 °C
      Maximum permissible temperature with borosilicate glass: 320 °C 320 °C
      Pressure: depending on the area of application

      Technical information:

      Muscovit mica Phlogopit mica
      Coefficient of expansion: 90 x 10–7 (K–¹) 135 x 10–7 (K–¹)
      Young's modulus: 180 x 10-³ (N/mm²) 170 x 10-³ (N/mm²)
      Thermal conductivity: 0,25 ... 0,75 (W/(m·K)) ~ 1,7 (W/(m·K))

      Other properties:

      Muskovit Glimmer Phlogopit Glimmer
      Radiation resistance: very good very good
      Resistance to organic solvents: constant constant
      Acid resistance: resistant (except hydrogen fluoride) resistant (except hydrogen fluoride)
      Oil resistance: constant constant
      Colour: reddish, green, colourless, brown amber, green

      FEP protective discs

      Product specifications: Protective disc

      Material: FEP (Perfluoroethylene propylene)

      For resistances and further information, please see our info data sheet.

      INFO Data sheet FEP protective screen - Chemical protection: DOWNLOAD

      FEP protective discs can be used if the sight glass plates, for example made of borosilicate glass, are exposed to strong chemical stress. At elevated pH values, such as alkalis with a pH value of 14, sight glass plates made of soda-lime glass or borosilicate glass are no longer recommended for safe and long-lasting operation. Here, for safety and cost reasons, the use of FEP protective discs is suitable.

      FEP is very similar to PTFE in terms of material properties. The most significant difference is probably the transparency. Depending on its thickness, FEP is transparent to milky bluish. Due to its good light transmission, a process medium behind it can be easily recognised. By using an FEP protective screen, the aggressive process medium behind it cannot attack the pressure-bearing sight glass plate.

      The transparency of FEP protective screens varies depending on the thickness. The process medium is always clearly visible in all delivery thicknesses. The application determines the thickness of the FEP protective screen.

      Operating conditions:

      Temperature: up to 200 °C / 392 °F

      Pressure: depending on the area of application

      Technical information:

      Young's modulus: 30 N/mm²

      Thermal conductivity at 23 °C / 73.4 °F: 0,25 W/(m·Kg)

      Measuring equipment

      Calipers are precision instruments that can measure both internal and external ranges/distances with very high accuracy. The measurement results are interpreted by the operator using the instrument scale. Manual calipers have two scales, the main scale and the vernier. Compared to digital calipers, no battery is needed here, but reading and interpreting the measured value is more difficult.

      To measure the outer dimensions of an object, the object is placed in the outer legs. The legs are pushed together until the object is held.

      The first significant digit is read from the main scale, immediately to the left of the "zero" on the vernier scale. In the example shown, this is 23.

      The decimal place is now determined on the vernier scale. The numerical value on the vernier scale is searched for whose scale line lies exactly on top of any scale line on the main scale. In the example, this is the value 6 on the vernier scale. This results in a reading of 23.6. Make sure that the main scale and the vernier are always viewed parallel and never read sideways. This prevents parallax errors and thus incorrect measurement results.

      Reflex and transparent glass

      Transparent sight glasses DIN 7081

      Transparent  sight glasses have a smooth surface on both the medium and atmospheric sides. These glasses are mostly used in longitudinal sight glasses with open housings on both sides for mounting on containers or pipelines.

      INFO Data sheet Reflex and transparent glass - differences and application: DOWNLOAD

      Installation example transparent sight glass
      Functional principle transparent glass

      The smooth surface has the advantage that mica protection screens can be used for applications with particularly aggressive media. This is not possible with reflex sightglasses!

      Reflex sight glasses DIN 7081

      A reflex sight glass is used to read the liquid level directly with the eyes or by using
      a camera. On the medium side, grooves are pressed into the reflex sight glass, which make the level clearer and easier to read. They are mostly installed in closed fittings such as level indicators.

      Installation example reflex sight glass
      Functional principle of reflex sight glass

      The principle of reflex sight glass is based on the difference in the refractive indices of liquid and gas or water and steam. The liquid level shows a striking dark colour for the liquid space and a bright white colour for the empty or gas space.


      Vacuum (bara / barg)

      In technology, the term "vacuum" is always used when, under normal conditions, there is significantly less pressure than atmospheric pressure in a predefined vessel / room / tank. By removing the internal pressure, a mechanical, inwardly directed load builds up in a vessel / room / tank due to the external pressure. The technical vacuum can be divided into several qualities / categories. The vacuum created is defined according to the remaining amount of matter in the vessel / tank / room. In industry, the rough vacuum is mostly used, whereas in medical / chemical technology, fine vacuum and below is often used. Pascal (Pa), millibar (mbar) or Torr (torr / mmHg) is normally used as the unit of measurement.

      Diagram comparison bara and barg for vacuum Table pressure range of vacuum

      Comparison ANSI Class and nominal pressure

      The pressure rating defines the maximum allowable pressure that a flange can withstand at a given temperature. According to the ANSI/ASME B16.5 specification, there are the following seven flange pressure classes: Class 150#, Class 300#, Class 400#, Class 600#, Class 900#, Class 1500# and Class 2500#.

      In the table shown, these ANSI flange pressure ratings are assigned to the nominal pressure. However, depending on the material and temperature, the respective operating pressures can be found in the corresponding pressure-temperature assignments.

      The terms "pressure rating", "class", "#", "Lb" or "Lbs" are not firmly defined, they all refer to the pressure-temperature assignment of a flange.

      Table comparison ANSI Class and nominal pressure DIN

      INFO Data sheet Comparison ANSI Class and nominal pressure: DOWNLOAD

      Comparison DN and NPS

      The nominal width DN is a dimensionless number that defines the inner diameter of a pipeline or the connection dimension of a fitting. The nominal diameter DN indicates the approximate inner diameter of the pipeline in millimetres and is based on the metric system of measurement.

      The designation Nominal Pipe Size, also called NPS, also quantifies the inner diameter of a pipeline or the connection dimension of a fitting. This definition also specifies the approximate internal diameter of the pipeline, but the information is given in inches, which originates from the Anglo-American system of measurement.

      INFO Data sheet comparison DN and NPS: DOWNLOAD

      table Comparison DN and NPS
      +49 (0) 2461 91634 00
      info@aci24.com