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For flange mounting
Execution according to DIN 28121 for working pressure up to 25 barg
Non binding • Usually a response within 24 hours
The round sight glass fitting Type 321 according to DIN 28121 is designed for flange mounting on vessels, tanks and apparatus. It is bolted onto an existing connection flange according to DIN EN 1092-1 PN 10 or PN 25 and enables observation or illumination of the vessel interior.
Type 321 is supplied factory pre-assembled and can be mounted directly onto a suitable flange without additional pre-assembly work. This makes the fitting particularly suitable for applications requiring a robust, easy-to-install and replaceable flange-mounted solution for operating pressures up to 10 or 25 barg.
The vessel sight glass Type 321 is manufactured as standard from stainless steel 1.4571. This material provides a reliable basis for industrial applications and is suitable for use as a round sight glass fitting for flange mounting. Stainless steel 1.4404 is also available depending on the version.
Borosilicate glass according to DIN 7080 is used as the sight glass plate. On the media side, the fitting is equipped with a PTFE-enveloped corrugated gasket. Due to the force shunt sealing design, the flange parts rest directly on each other, so retightening the clamping screws is no longer required.
Various options are available for adapting the fitting to different operating conditions. These include SGW sight glass wipers with PTFE or silicone wiper blades, SVII spraying devices and LED lights for hazardous and non-hazardous areas.
For increased temperature loads or steam applications, a mica protection screen can be used. For applications involving aggressive chemicals or alkalis, FEP or Halar® coatings are available.
Special designs can be reviewed and implemented according to the application. These include, for example, a version for flange connections with a PN 16 bolt pattern.
The vessel sight glass is particularly suitable for vessels and apparatus where a connection flange according to DIN EN 1092-1 PN 10 or PN 25 is already available and safe visual inspection of the vessel interior is required.
Typical applications for Type 321 include process vessels, storage tanks and technical apparatus in the chemical and water technology sectors, where media or process conditions must be reliably observed under operating pressures up to 10 or 25 barg. The pre-assembled design makes the fitting especially suitable wherever an easy-to-install solution with low replacement effort is required.
| DN | 40 | 50 | 80 | 100 | 125 | 150 | 200 |
|---|---|---|---|---|---|---|---|
| Di [mm] | 48 | 65 | 80 | 100 | 125 | 125 | 150 |
| H [mm] | 36 | 38 | 46 | 46 | 54 | 54 | 54 |
| Da [mm] | 150 | 165 | 200 | 220 | 250 | 285 | 340 |
| L [mm] | 18 | 18 | 18 | 18 | 18 | 22 | 22 |
| K [mm] | 110 | 125 | 160 | 180 | 210 | 240 | 295 |
| Weight [kg] | 3,8 | 4,6 | 8,2 | 9,3 | 13,8 | 19,5 | 28,7 |
| H [mm] | 38 | 41 | 50 | 59 | 66 | 66 | 66 |
| Da [mm] | 150 | 165 | 200 | 235 | 270 | 300 | 360 |
| L [mm] | 18 | 18 | 18 | 22 | 26 | 26 | 26 |
| K [mm] | 110 | 125 | 160 | 190 | 220 | 250 | 310 |
| Weight [kg] | 4 | 5 | 8,9 | 14 | 20 | 26,9 | 39,3 |
The Type 321 is the ideal solution when the tank sight glass is to be mounted on an existing flange in accordance with DIN EN 1092-1 and a design compliant with DIN 28121 is required for operating pressures up to 10 or 25 bar gauge.
The Type 321 is designed as a round sight glass assembly in accordance with DIN 28121. The standard specifies the design of flange-mounted sight glasses for tanks and thus provides the basis for their use on existing flanges in accordance with DIN EN 1092-1 PN 10 or PN 25..
The Type 321 is delivered pre-assembled and can be mounted directly onto a compatible flange. This reduces on-site installation time and also makes it easier to replace the entire valve in the event of damage.
The Type 321 features a PTFE-coated corrugated ring seal on the media side. This seal operates in a force-balanced configuration and helps ensure optimal process reliability.
For the Type 321, options include SGW wipers, SVII spray nozzles, LED lights, spark-proof screens, and FEP or Halar® coatings. Custom designs are also available.
