It might be surprising for many to find that a large variety of valves have a place in ships – without the right type of valves, a ship cannot function properly. Be it the valves used for interior plumbing, or the valves used in the engine room for effective functioning, valves used onboard ship play a crucial role in safeguarding the smooth running of the said ship.
Valves find many applications in ships. Also, many types of valves used in ships serve various purposes. This guide will elaborate on the types of valves used on ships and each of their functions.
Some Common Applications of Valves Used in Ship
A wide variety of valves are used on ships, like ball valve, butterfly valve, and they all have unique applications. But in general, valves are used to control and regulate the flow of fluids on board and manage the ship’s optimal functioning. Valves used in ships can also carry gasses, vapors, and mixtures, so they find innumerable applications.
Usually, valves serve purposes including:
- Regulating liquid flow
- Relieving pressure
- Starting/stopping flow
- Increasing/decreasing flow
But specifically, there are two main applications for different types of valves used in ships – bilge systems and ballast control. Ballast controlling is the process of loading and unloading seawater from the ship when it is docked at the port. The ballast water keeps the ship stable when there is an absence of cargo.
The bilge is the lowest part of a ship – this is the place where excess water is collected. With the usage of valves and pumps, the accumulated water is pumped out of the ship.
Marine valves are different from basic valves used on dry land. An industrial valve manufacturer who supplies marine valves will make sure to manufacture these parts from material that is resistant to corrosion and also withstands seawater.
A ball valve is an industrial valve that controls the flow of a fluid with the help of a hollow, perforated ball. A shut-off valve, this type of valve allows or stops the flowing fluid when the rotatory ball with a bore in it is adjusted. The industrial valve can either be operated manually or through an automated device.
The rotatory ball is turned 90° (also known as a quarter-turn) to let the fluid flow or stop. These valves commonly find applications as shut-off valves, but specially designed ball valves can are also used as control valves.
Ball valves are often preferred for a wide range of applications because of their durability. These valves have resistance against many media, including mixed media like slurries. Marine ball valves are built from corrosion-resistant materials – they are also designed to withstand seawater.
Usually, floating ball valves find many applications in marine systems because they prevent leakage and ensure the safe transmission of fluids. All ball valves appear in different sizes with different sizes being suitable for different applications.
Ball valves withstand high pressure; hence they are suitable for controlling oil and gas flow. These industrial valves are lightweight and compact, making them a great choice for marine applications. Built to last long, ball valves work excellently, even in high pressure and temperature situations.
Butterfly valves are of a simple build and are used mainly in shut-off functions. They are not generally used for regulating the flow of any medium because they do not have proper sealing properties. In this industrial valve, a disk is connected to a rod, and this setup is known as the “butterfly”.
Like ball valves, these industrial valves are also quarter-turn rotational valves – by rotating the disk for 90°, the valve can be closed or opened. These valves can either be manually operated or handled through automated motors. The design of a butterfly valve lies in a way that it eliminates the contact between the flowing media and the body of the pipeline.
There are many types of butterfly valves – some of the common ones include wafer-type butterfly valves and triple offset butterfly valves.
Butterfly valves are usually employed in three types of applications – constant load, throttling, and space-restrictive applications. Butterfly valves are perfect in space-restrictive environments because they are compact and light – they can be easily placed in tight corners.
As for marine applications, butterfly valves are suitable for handling fuel, lube oil, and other heavy media. These valves also find application in freshwater, seawater, and chilled water systems. Butterfly valves are easy to install and maintain, and they offer excellent sealing properties.
For the smooth functioning of a system and avoiding backflow in a pipeline, butterfly valves can be a great option. They are also highly corrosion-resistant, so they are perfect for marine applications.
One of the most common types of valves found in any kind of water supply system, gate valves are widely used for their effective isolation feature. These valves are also known as slide valves as a closure element slides in to shut off or let the media flow. This is a linear motion valve.
Wherever a shut-off valve is needed, gate valves can be a great option to consider. But it should be noted that they cannot handle high-pressure situations. Also, these valves can create low-pressure drops – these valves reduce pressure drops across the valve in the fully open position.
In situations that require on-off services, gate valves are employed. It is even better if these valves are placed in situations where the usage is infrequent. These valves are among the most common types of valves used onboard ship.
Gate valves come in some variations, but the main ones are rising stem design and non-rising stem design. Out of these two, the non-rising stem valves are widely employed in ships because they are small and don’t take up much space. Usually, these valves are found in lower levels of a ship or narrow vertical spaces.
The valve’s stem is either raised or lowered as per the function – it is indeed like a gate. Based on the position, the medium flows or stops. Gate valves are a perfect choice when slurries are involved, as these valves easily cut through the flow.
If a system requires a regulated flow of any media, then globe valves can be the perfect fit. Globe valves are linear motion valves that can stop/start, and regulate the effective flow of a medium. These valves are spherical – the two parts of the body of a globe valve are divided with an internal baffle.
Also known as throttle valves, these valves utilize the perpendicular motion of the disk to regulate the motion of media in a pipeline. While other valves, like ball valves and butterfly valves, might not be the suitable choice for the regulation of fluids, globe valves act as the perfect option for the function.
The structure and functionality of a globe valve permit it to regulate media in both directions in a pipeline. This valve is commonly found in water faucets. Apart from manual handling, these valves are also controlled using electric and pneumatic actuators, especially in large-scale applications.
The movable disk and the stationary ring seat present in a globe valve allow it to regulate the flow of a medium through a pipe in ships. As these valves are capable of handling variable pressure situations, they are employed in emergency bilge sections.
Another dynamic application of this valve is preventing the backflow of a medium. Screw down non-return valve is a type of globe valve that is particularly used for this function.
These valves have a long life, making them a suitable choice for marine applications. A finer degree of control of media can be attained by opting for globe valves with specific profiles.
A check valve’s main purpose is to ensure that there is no backflow. These valves allow the flow of a medium in only one direction and work on the pressure difference. The build of the valve is very simple – it is a small cylinder with two ports that act as the inlet and outlet. Check valves are usually referred to as “non-return valves”.
The mechanism of the valve depends on its various types – a basic check valve allows the flow of medium when the inlet side has a higher pressure. The specialty of these valves is that they do not need a handling mechanism, be it mechanical or automated. These valves come in handy in any situation where backflow will cause an issue.
There are a wide variety of check valves – swing check valves, lift check valves, and ball check valves are some common ones.
In the marine industry, check valves are used in many cases including desalination, hydraulics, and fuel handling. As one of the common types of valves used onboard ship, these valves can also be employed in complex and crucial environments according to the need.
As the main function of a check valve is to prevent backflow, this type of valve is incredibly useful on ships. Be it maintaining contaminated media or acting as a vacuum manager, check valves get the job done well. They are also easy to install because of their compact build and require little maintenance.
Valves play a crucial role in any system involving transmission of different media. This emphasizes why industrial valves are fundamental to any ship. The function of the different types of valves used in ships varies, but every type of valve is important for the smooth functioning of a ship.
Also, marine valves need to be manufactured by following several protocols, because they need to withstand higher wear and tear. Get in touch with DomBor Valves today and find the perfect types of valves for marine applications.