Isolation valves for gas distribution networks
Leakage is not acceptable in gas networks, so valve requirements are stricter than for water. Here is what operators choose and what they check.
TAZ Engineering Team · · 6 min
Ball valves as the default
Medium and low pressure gas distribution now mostly uses ball valves: quarter-turn closing, tight shut-off and almost no maintenance. Buried service uses fully welded valves with extended stems.
Gate valves on gas
Steel gate valves remain on older networks and large diameters. Valves rated only for water must not be used on gas: seal materials, packing tightness and air testing all matter.
Tightness
GOST 9544 class A, with no visible leakage during the test, is the usual requirement for gas. Testing is done with air or nitrogen as well as water. Check that the class appears in the passport.
Installation and documents
Above-ground valves need corrosion protection and protection against unauthorised operation; buried valves need surface boxes and markers. The gas utility will ask for a passport naming the medium and conformity documents, so agree requirements in advance.
Checklist
- network pressure
- DN
- ball valve or gate valve
- leakage class A
- buried or above ground
- documents for the utility