Socket Weld & Threaded Ends

The socket-weld connection is normally a better pressure containment joint than the threaded joint.

So the valve would be installed with the socket-weld end on the up-stream (high pressure) side and the threaded end on the lower (or non-pressure) side.

Valves with this type if end connections are normally used for:

a) - A High Point Vent with the threaded side plugged

b) - A Low Point Drain with the threaded side piped to a drain funnel or plugged

c) - A PI (Pressure Indicator) Root valve

d) - A Sample Point Root Valve

Notes:

1. A 'Root Valve' is the valve that performs the function of primary shut-off of a branch from a main line.

2. Piping drawings (Isometrics, etc.) need to carry instructions so the valve is installed properly.

I hope this is helpful.

It is important that the replacement valve is identical in ANSI class rating and service rating, and the valve connection configuration must match the original valve.

Examples:

If the original valve is socket weld on both sides the replacement must be socket weld on both sides.

If the original valve is socket weld on the upstream HP side and threaded on the downstream outlet LP side then the replacement valve must be the same configuration.

Failure to follow strict valve replacement requirements can/will result in severe safety and performance consequences.