This TDS was made after a customer asked how we could mark the same valve with both “1/2 psi,” and “600 CWP.”

BONOMI INDUSTRIES SRL ball valves are approved under several different specs, each of which requires us to put certain markings on the valve.

  • ANSI Z21.15/CGA 9.1 – Standard for Manually-Operated Gas Valves for Appliances, Appliance Connector Valves and Hose End Valves
  • AGA Requirement 3-88 – Manually Operated Gas Valves for use in House Piping Systems
  • UL listing YSDT – LP Gas Shut-off Valves.
  • ANSI ASME B.16.33 – Manually Operated Metallic Gas Valves for Use in Gas Piping Systems up to 125 psig
  • FM Class 1140 – Quick Opening Valves ¼ Inch Through 2 Inch Nominal Size
  • UL listing YRBX – Flammable Liquid Shut-off Valves

The marking requirements of these different specs are quite different. For example:

  • ANSI Z 21.15/CGA 9.1 requires “A permanent marking specifying the maximum pressure rating of ½ psi shall be provided on each valve.”
  • AGA Requirement 3-88 requires “Valves shall be marked as required in MSS SP 25 --- which in turn requires “The designation 2G for a valve rated at 2 psig, or 5G for a valve rated at 5 psig, shall be shown on the head, stem, or body.”
  • FM Class 1140 – “Each valve shall be permanently marked with the following information:
    • Manufacturer’s name or trademark:
    • Nominal valve size;
    • Year of manufacture
    • Rated working pressure (in our case 450 or 600 CWP)

To comply with all of these requirements BONOMI INDUSTRIES SRL must put several different pressure markings on the valves, and it is natural that these marks should seem to contradict one another. But in fact it is quite possible that a particular valve may meet the requirements of several of these different specs, and so be
permanently marked with several different pressure ratings. For example, the RuB s.195 valves are marked with 450 CWP, 5G, and 1/2 psi. And RuB s.95 valves are marked 600 CWP, 5G, FM 400 WP, and 1/2 psi.

The 1/2 psi mark does not restrict the valve to that pressure. What it means is that the valve has also been tested and approved for use in gas appliance connections in buildings. The tests and design requirements necessary for that approval include a long list of safety and efficiency requirements – for example: operating torque, hammer blow shock resistance, gas flow capacity, fire testing, torsional strength when the valve is screwed onto a pipe, etc. etc. These requirements are not merely pressure limits. They are safety issues for a particular type of gas service, of which pressure limits are a very small part. But the specification requires us to mark the valve that way, to show that we have passed the various tests for that service.