A Brief Multivalve Brief

There are two different manufacturer valves installed on the risers of the underground LPG tanks – Cavagna and Rego. They are threaded onto the tank atop the riser pipe sticking out of the ground, which is protected by the composite underground dome assembly and lid after the tank is buried during the installation. While the two valves serve the same purpose, they are slightly different in functionality.

The Rego Multivalves are designed for use in single opening ASME underground containers. They thread onto the end of the riser with a 2 ½ inch M. NPT connection. The multivalve combines a double back check filler valve, a vapor equalizing valve with the excess flow, a pressure relief valve with protective cap and chain, a service line shut-off valve, a fixed liquid level gauge, a junior size float gauge flange opening, and a plugged pressure gauge opening into this one-piece unit, or “cluster”. When using the Rego valve, a separate opening is required for liquid withdrawal on the body of the tank. While the location is not ideal for evacuating a tank if necessary, it is in a much safer location if the multivalve becomes compromised by some outside source (backhoe, mower, tractor, etc...) In addition, the Rego valve has the Presto-Tap fitting installed in the multivalve, allowing for a quicker and easier leak test procedure.

The Cavagna Group offers a very comparable valve that serves the same main purposes on underground tanks. The multi-service valve contains the same valving arrangement as the Rego valve, with one main difference. Cavagna offers the valve with the liquid withdrawal valve integrated into the body of the valve. This makes it much easier to reach if evacuating the tank becomes necessary. It also eliminates the need for an additional opening on the body of the underground tank. However, while the liquid valve has a lower profile on the cluster than the other ports, it still poses some risk if the multi-service valve is clipped.