LPG VALVE MANUFACTURING

Valves are a type of mechanical device that are implemented to regulate flow, pressure, or both, within a system. They an integral aspect of any piping system that requires a fair amount of control. The primary functions of a conventional valve comprise flow control in the form of rate of flow and the direction of flow. Valves are thus used to prevent back flow, and relieving pressure. The various valve types, designs, and models can be functional in specific industrial, commercial, and residential applications.

LPG valves may need to be designed especially for maintaining high pressure within the cylinder and to let out the gas at a rate specified and within regulatory permission. These valves are also designed to withstand the possible damage they may take during transportation. An additional cap is often screwed over the valve in order to further reduce the likelihood of gas leakage when the cylinder is not in use.

The gas cylinder valve is the primary safety mechanism on a gas cylinder and shall not be tampered with. It is a device used to contain the contents of the cylinder that is under pressure. Cylinder valves are fitted with pressure relief valves of different types (depending on the cylinder) to protect against catastrophic failure of the cylinder valve.

Cylinder valves open in an anticlockwise direction and close in a clockwise direction. Valves shall never be opened without a regulator attached. Always open cylinder valves slowly

There two basic types of LP Gas cylinder valves for vapour service, namely, self-closing, clip-on valves and hand wheel operated valves. They can come with or without pressure relief valves depending on local regulations.

1. Self-Closing, Clip-on Valve

These are typically used for domestic cylinders where low cost and fit for service valves are required. Common types in the market are compact, bayonet, or snap on (snap tight) valves. They can be fitted with excess flow limiters and/or anti-dirt tubes (also called education tubes). Because these valves are open-topped, plastic dust caps are recommended to be fitted during storage and transportation to prevent entry of foreign matter.

Performance Requirements

i. The valve shall be of the self-closing type, closed by gas pressure in the cylinder assisted by a small stainless steel spring.

ii. The valve shall be completely gas-tight and shall have no regulating function that can restrict high filling rates.

iii. The 13kg and 50kg cylinder valves shall be with a safety relief valve. The 3kg and 6kg cylinder shall be fitted with camping valves.

iv. If it is with a safety relief valve, then the safety relief valve shall be of pop-action type and shall have a set pressure of 2.55 MPa.

v. The safety relief valve shall open to allow blow-off should the cylinder pressure under extreme conditions reach 2.94MPa.

vi. The capacity of the safety relief valve when fully open shall be 5.0 cubic meters of air per minute.

vii. The spindle shall be able to move freely.

2. Hand Wheel Operated Valve

These valves are used both with domestic and commercial cylinders and are designed for different applications i.e. liquid fill, liquid service and vapour service. The outlet connection of hand wheel operated valves can come in different forms e.g. CGA 510 (or F.Pol), CGA 555 (or M.Pol), ACME, NPT, etc. When both vapour and liquid connections are on the same valve, they must be designed differently for clear distinction. Liquid service valves are fitted with a tube and an excess flow limiter. Hand wheel operated valves can accidentally be opened and it is recommended to fit a gas tight plug after filling while the cylinder is in transport or storage.