Bellows Sealed Stop Valves


The high integrity A3S bellows sealed valve is suitable for use under higher pressure steam, gas, and liquid applications as it is designed to ASME Class 800.

Technical Illustration

A3S and A3SS Bellows Sealed Stop Valve

A screwed and socket weld bellows sealed, in-line stop valve for use on steam, gas, liquid, condensate and water systems.

Tech promo A3S and A3SS

Teknisk Information

Sizes and pipe connection

½", ¾", 1", 1¼", 1½" and 2"

Screwed BSP (BS 21 parallel), NPT

Socket weld to BS 3799 /ANSI B 16.11

Pressure / temperature limits (Class 800)

Body design conditions 

Class 800
PMA Maximum allowable pressure  136 bar g
TMA Maximum allowable temperature 425°C
Minimum allowable temperature  -29°C
PMO Maximum operating pressure  99 bar g @ 360°C
Maximum operating pressure for extended bellows life 40 bar g @ 400°C
TMO  Maximum operating temperature  425°C
Maximum operating temperature for extended bellows life 400°C @ 40 bar g
Minimum operating temperature  -29°C
Without the bellows fitted the unit is designed for a maximum cold hydraulic test pressure of:  212 bar g

Teknisk Information


A3S and A3SS Bellows Sealed Stop Valves



reference number



Download PDF

Installation & Underhålls Instruktioner

document language reference number download
A3S Bellows Sealed Stop Valve English IM-P132-11 Download PDF
A3S Bälgtätad avstängningsventil Swedish IM-P132-11 Download PDF


Vi hjälper dig att hitta rätt lösning för Dig

+46 (0)8 556 322 30

Prata med Ditt lokala team

Kontakta oss

Vi återkommer till Dig snarast

Your closest Spirax Sarco is

Spirax Sarco

This region has not yet joined our new website. You will now continue to the existing site for Spirax Sarco