Cast Steel Globe Valve

Product Introduction

What is cast steel globe valve?

The cast steel globe valve uses cast steel body material and stainless steel trim. When the nominal pressure PN ≤ 16MPa, the forward flow is generally adopted, and the medium flows upward from the bottom of the valve disc; when the nominal pressure PN ≥ 20MPa, the counter flow is generally adopted, and the medium flows downward from the top of the valve disc to increase the sealing performance. When in use, the globe valve medium can only flow in one direction and cannot change the flow direction.

Cast steel globe valves are usually made of carbon steel, so many people directly think that cast steel globe valves are carbon steel globe valves or wcb globe valves. The most commonly used sizes are 2 inch globe valve, 8 inch globe valve, or It is expressed by the nominal diameter, such as globe valve dn50, globe valve dn200, etc.; according to the purpose of the valve, it can also be called oxygen globe valve, modulating steam valve, modulating steam control valve, etc.; many globe valves need to be used with actuators Yes, so it can also be called an actuated globe valve.

The structure of cast steel globe valve

The main components of a globe valve are the actuator, valve stem, valve body, valve plate, valve seat, valve cover and some form of sealing device (packing).

The disc is mounted at right angles to the seat surface, which generally results in a better sealing arrangement than gate valves. As the disc descends and rises, it is guided by guide vanes, pistons or valve stems.

Packing is installed between the stem and the bonnet to ensure that the valve does not leak.

Some globe valves connect the stem directly to the disc, but some designs do not. A screw-in check (SDNR) valve is one such design, in which the valve stem is not connected to the disc. SDNR valves are used in safety critical systems such as ship bilge systems and boiler feed water systems.

Flanges are installed on the suction and discharge sides of the valve to facilitate piping connections.

Advantages of cast steel globe valve

Due to the circular shape of the disc and seat, uneven wear in the machined area is unusual.

Globe valves can be used for throttling (flow control), but due to the larger circular shape of the disc, the valve does not provide a great degree of control. If fine-tuning of flow is required, the globe valve design may not be optimal.

Disadvantages of cast steel globe valve

When the valve is throttled, globe valves are subject to high pressure drops, which can cause damage to valve components.

Due to incorrect operation, globe valves are often stuck open. The shut-off valve should be fully open, then reverse the handle 180 degrees to close the valve slightly again. If this “rewind” procedure does not occur, the valve can get stuck in the open position, making it difficult for the operator to locate the valve; this causes the operator to attempt to open a valve that is already fully open, which can result in a broken/broken valve stem.

The main application of cast steel globe valve

1. It is used on the water vapor system pipelines in the petroleum, chemical, power station and boiler industries.

2. It is used in gas-liquid separation and liquid purification equipment in oil refineries and chemical plants.

3. It is used in the non-return device of the pipeline system on the ship to ensure that the pipeline system will not flow backward due to fluid pressure.

4. The connection between LNG station pipeline and associated gas.

5. In the high temperature and high pressure ash conveying system of thermal power station, it is used as a valve for overpressure discharge.

6. The valve body material for nuclear industry is WC6, which is suitable for high temperature, high pressure and corrosion resistance occasions.

7. The gate valve of the oilfield water injection pipeline generally adopts a welded structure.

8. Control components in the technological process of petrochemical enterprises.

9. Bidirectional opening and closing of the urban heating system pipe network.

10. Heating furnace control system in metallurgical industry.

11. Media conditioning in paper sizing systems.

12. Filtration of sewage treatment system.

13. Dark rod cast iron gate for mine drainage.

14. Safety devices for gas pipelines in the petrochemical industry.

15. Piping of fire water supply system.

16. Decompression and voltage stabilization facilities for water supply systems in high-rise buildings.