What are the different types of valves used in HVAC?

In the Heating Ventilation and Air Conditioning（HVAC）system, gate valve, butterfly valve, ball valve, globe valve, these four kinds of valves will definitely be used. This article will introduce you in detail.

1. Gate valve

Mainly used for various shutdown points, widely used. Most of the air-conditioning water systems use soft-sealed gate valves with reliable sealing. The maximum diameter of the gate valve can reach DN1400, and the sealing performance is better than that of the butterfly valve on the pressure pipeline below 16 kg. Cast steel gate valves and stainless steel gate valves do not meet the standards of the Ministry of Construction and are not suitable for building water systems. They are mostly used for high temperature and high pressure, oil and gas media.

2. Butterfly valve

A centerline butterfly valve is recommended because it can bear pressure in both directions, and an eccentric butterfly valve is not recommended. When the pressure is above PN16, it is not recommended to use a butterfly valve; below DN50, it is not suitable to use a butterfly valve, and a globe valve can be used. The air-conditioning water system is not suitable for metal hard-sealed butterfly valves or PTFE butterfly valves. The air-conditioning water system mostly uses rubber soft-sealed butterfly valves. Generally, ductile iron valve bodies and midline butterfly plates are used. The temperature resistance of EPDM rubber can reach 100 °C, which can fully meet the Requirements for heating and air conditioning systems.

3.Globe valve

The globe valve has large resistance, reliable shut-off and large volume. There are metal seals and rubber seals, and the production process is relatively simple. In the shut-off valve, the resistance is large, but it can be adjusted manually, which can play a role of manual balance if necessary, and has strong anti-cavitation ability. DN50 and below are mostly threaded connections; pay attention to the direction of water flow; stop valves should not be used above DN200, because the shut-off force is too large, and it can hardly be shut off manually.

4.Ball valve

DN50 and below are connected by all-copper valve body, the ball is stainless steel, and the sealing ring is tetrafluoroethylene.