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The Beginner’s Guide To Ship Valves

The Beginner’s Guide To Ship Valves

There are 430 ships and submarines in the U.S. Navy today. They run the gamut from amphibious assault ships to destroyers. The newest ship in the fleet is the high-tech Gerald R. Ford-class aircraft carrier, which measures an impressive 1,106-ft. and can accommodate over 75 aircraft.

No matter their size or purpose, Navy ships all have one thing in common…valves. What types of valves are needed for building ships? CPV Manufacturing explains.

The Importance of Valves in Building Ships

Why are valves necessary for shipbuilding? Ships need valves to regulate the pressure and flow of fluids in the various onboard systems. Along with liquids, valves can also transfer gases, vapors, and slurries or semi-liquid mixtures.

Each type of valve serves a different purpose:

• Stop/start flow

• Reduce/increase flow

• Control direction of flow

• Regulate flow or pressure

• Relieve pressure from pipe systems 

Valves are made up of several different components.

First is the valve body (shell), which holds all of the components together.

There is a bonnet, which covers the opening.

Valve trim refers to the internal parts.

Valve disks are designed to throttle or stop flow

Seal rings provide a seat for the disks

Valve stems help control the closing of the valve 

So, which ship valves are used on Naval vessels and what purpose do they serve? Let’s take a look at four types.

1. Gate Valves

Gate valves are one of the most common types of valves used on any type of ship. They control the flow of liquid through the pipes by raising or lowering, just like a gate. While they have a relatively simple design and function, gate valves have a number of variations.

Rising stem design – Threads are mated with internal threads on the inside the bonnet.

Non-rising stem design – The valve disc is internally threaded and connects with the stem.

Both variations serve different purposes.

2. Butterfly Valves

Butterfly valves are lightweight and used for ships that operate with fuel, freshwater, lube oil, or chilled water systems. They work much the same as throttle and choke valves in your car.

If you imagine a butterfly moving its wings, you’ll understand how this type of valve works. The central disk pivots to open and close the valve as the shaft turns.

3. Globe Valves

Globe valves in shipping can regulate flow through a pipe by means of a movable disk and stationary ring seat. An angle valve allows for reverse flow.

There are different variations of globe valves, including screw-lift and screw down non return. 

4. Relief Valves

Relief valves are designed to “relieve” pressure inside the pipes. When pressure increases, a spring inside the valve opens. The spring can be adjusted so the valve opens faster or slower, as needed.

There are also different variations of relief valves, including self-regulating valves and automatic process control valves. The later are used mainly for unmanned machinery.

Learn More About Valves for Navy Ships

Valves may be small, but they serve a big purpose in ensuring smooth sailing for Naval vessels and other ships. Once you know what each type does, you can better understand why they are necessary when building ships.

If you want to learn more about valves and how they work, check out the latest news in shipbuilding.