POL vs QCC valve: what is the difference and how to choose a cylinder valve

When ordering LPG cylinders in batches, the first question about valves is usually: POL vs QCC valve — which one? The two valve types differ in how they connect to the regulator, how they are fitted and removed, and in some safety features. Choosing the wrong type may leave the cylinders unable to connect to the equipment commonly used in your market. This article explains the differences and how to choose.

What is a POL valve?

POL (short for Prest-O-Lite, the name of a connection type that dates back a very long time) is a valve with a left-hand thread inside the valve outlet. The connector of the regulator or filling hose is screwed into the valve outlet and usually has to be tightened with a spanner to seal.

• Simple, durable design that has been used for many years in many markets.
• Slower to connect and disconnect because a tool is needed; the left-hand thread can confuse people who are not used to it.
• The seal depends on tightening to the correct torque and on the condition of the connector.

What is a QCC valve?

QCC (Quick Closing Coupling, called Type 1 in some markets) is a valve with a large external thread; the regulator connector has a large handwheel and is screwed on by hand without any tools.

• Quick to connect and disconnect, convenient for end users.
• The design usually includes a mechanism that stops gas flowing when the connector is not fitted correctly; some types have additional safety features depending on the valve manufacturer.
• Many QCC connectors are still backward compatible with POL-type valve outlets, but this needs to be checked for each specific valve.

POL vs QCC valve at a glance

Besides POL and QCC, there are other valve types on the market, such as clip-on valves (where the regulator is fitted with a clip-on coupling). In Vietnam, the common valve type varies by brand and region.

How to choose a valve when ordering LPG cylinders in batches

1. Check the equipment your customers use: the type of regulator and the filling heads at your own filling plant or your partner’s.
2. Check your sales market: each country and region has its own common connection standard; for export orders, ask carefully about the importing country’s requirements — see exporting LPG cylinders.
3. Standardise across your whole cylinder fleet: using a single valve type keeps operations simple for the filling plant and dealers.
4. Ask for the valve documents: valves must have a known origin, certification of conformity to standards and be leak tested when fitted to the cylinder.

The valve type also affects the LPG cylinder price; some orders are for cylinders without valves fitted so the partner can fit their own.

Safety notes when using cylinder valves

• Check the washer and connector every time you change a cylinder; test for leaks with soapy water — see how to check for gas leaks.
• Do not remove or repair the cylinder valve or safety valve yourself.
• Only use a regulator of the right type for the cylinder valve.

Frequently asked questions

Written by the VietnhatGas technical and sales team — a batch manufacturer of LPG cylinders. This content is for reference; regulations and standards may change, so please check the current texts.