Brass Valves and Cock Fittings

Brass valves and cock fittings are compact shut-off, regulating and protection valves machined from brass for air, gas and fluid lines. Vikay supplies gas valves, needle valves, non-return (check) valves, air valves, F valves, and compressor delivery and safety valves in BSP and NPT sizes.

This range covers the small brass valves that sit at the ends of a line rather than in the main run: isolation, regulation, one-way protection and pressure relief.

Gas valves and cock fittings isolate LPG and appliance lines with a quarter-turn. Needle valves give fine, repeatable flow control for gauges, burners and instrument take-offs. Non-return valves hold flow in one direction and protect a compressor or pump from back-feed. Air valves and F valves serve pneumatic and tyre-inflation duty. Compressor delivery valves and compressor safety valves handle the discharge and relief functions on reciprocating air compressors, an area Vikay knows from its air-compressor spares business. Compressor flare elbows complete the discharge connection.

Bodies are turned from free-cutting brass to BS 2874 CZ121 / ASTM B16 C36000, with threads to ISO 228 (BSPP), ISO 7/1 (BSPT) or ASME B1.20.1 (NPT) and hose tails where the pattern calls for one. Sizes generally run 1/8 in to 1/2 in. For a safety valve, state the set pressure you need; for the others, state size, thread form and the medium.

Frequently Asked Questions

What is a cock fitting?

Cock is the older trade name for a simple quarter-turn plug or ball valve used to isolate a line, such as a gas cock, drain cock or test cock. The term still appears in gas and appliance work; functionally it is a compact manual shut-off valve.

What is the difference between a needle valve and a ball valve here?

A needle valve closes a tapered stem into a small seat, so flow changes gradually across several turns, so it is for metering and fine adjustment. A ball valve opens fully in a quarter turn and is for isolation, not throttling. Throttling a ball valve wears the seat and it will eventually pass when closed.

How is a compressor safety valve set?

Safety valves are supplied preset to a nominated relief pressure and are not adjustable in service. Specify the set pressure and connection size on your enquiry, and choose a set pressure above the compressor's normal cut-out but at or below the receiver's design pressure. A valve that lifts too readily is as much a problem as one that lifts too late.

Which way round does a non-return valve fit?

The arrow on the body points in the direction of permitted flow. Fitted backwards the valve closes against normal flow and blocks the line. On compressor discharge duty, fit it so the valve holds receiver pressure back from the pump when it stops.

Are these valves suitable for LPG and gas service?

The gas valves and cock fittings in this range are made for LPG and gas appliance duty with the corresponding thread forms. Local codes generally require gas fittings to be approved and installed by a competent person, so confirm the approval your market demands and we will advise which part numbers suit.