Valve 1-outlet AIR , DIN 232 bar, 3/4 BSP

Valve 1-outlet AIR , DIN 232 bar, 3/4 BSP

This 232 bar valve with a 3/4 BSP thread is designed to replace valves on diving cylinders that use this European conical/cylindrical thread standard.

Technical specifications of the 232 bar 3/4 BSP valve

•   Working pressure: 232 bar
•   Cylinder neck thread: 3/4 BSP (3/4 Gas) – 55° thread profile
•   Compatibility: steel or aluminium diving cylinders with 3/4 Gas standard threads

Technical compatibility and prevention of NPSM incompatibility risks

This valve is intended for owners of older diving regulators

In the replacement market, many valves based on the American 3/4 NPSM standard are incorrectly sold under the designation ‘3/4 GAS’. It is crucial to identify the difference in threading to avoid inspection failures and the risk of accidents caused by incompatibility.

• Profile incompatibility: the 3/4 NPSM thread has a thread angle of 60°, whilst the 3/4 BSP (Gas) thread has a thread angle of 55°. The two profiles are not machined to the same pitch and do not distribute pressure in the same way within the cylinder neck.
• Inspection ring test error: a 3/4 GAS threaded test ring known as a ‘NO GO’ ring (stop ring) may, by mistake, fit onto a 3/4 NPSM valve. This misleads the user by creating a false appearance of compatibility.
• Consequences during the TIV inspection / re-certification: the use of an NPSM valve on a 3/4 GAZ drum or the detection of non-compliant threading using inspection gauges results in the systematic and immediate rejection of the assembly during the TIV inspection or during periodic re-certification tests

Source: FFESSM CTD69