Valves are essential parts of any piping system used to control the flow and pressure of contents, whether that is oil, gas, liquid or vapors. Here is our list of 4 of the most commonly used oil and gas valves in the industry and the reasons for their existence, with details from Bundor:
A ball valve is a quarter-turn rotational motion valve that used a ball-shaped disk to control a flow. If the valve is opened, the holes in the ball stay in line with the body inlet allowing contents to pass.
The balls are generally made out of several metallics whilst the seats are made from soft materials like Teflon. The combination of materials means the ball valve can operate at temperatures as low as -200 deg C and as high as 500 deg C.
Mainly used for air, gases and liquids, ball valves are quick to turn on and off and have a tight sealing with low torque. The only downside to these valves are the lack of throttling properties available.
A quarter-turn rotational motion valve, the butterfly valves is used to stop, start and regulate flow. Easy and fast to open, the valve usually comes equipt with a gearbox where the hand wheel by gear is connected to they stem.
This simplifies the operation of the valve, but at the expense of speed. These valves must also be installed a minimum of 6 pipe diameters away from other line elements.
As well as being lightweight, and quick to use, the butterfly valves are available in large sizes and can cope with low-pressure drop and high-pressure recovery.
Gate valves are primarily designed to start or stop a flow when a straight line flow of fluid and minimum flow restriction are needed. In service, these valves are pretty much kept either fully open, or fully closed.
When turned open, the disc of the gate is completely removed allowing contents to pass. Although this gives the valve good shut-off properties and is bidirectional, they cannot be quickly opened or closed and are sensitive to vibration when open.
Typically used for cooling water systems, transporting fuel oil and turbine lube oil systems, a globe valve is a linear motion valve used to stop, start and regulate flow.
Conventionally used for isolation and throttling services, the globe has become the world's most common types of valves. With a good shut off ability, available in tee, wye and angle patterns and easy to machine the valve seats - its easy to see why they are so popular.
The slight disadvantages of the globe are that they perform unfavourably when high pressure drops, and require greater force or throttling flow under the seat to shut off valve.