Understanding The Mechanism Of Globe Valves
A valve is a device used for controlling the pathway of air or fluid. It is present in any mechanism that deals with liquid flow or airflow. There are valves present in our heart as well, controlling the blood flow. Just like that, water pipes contain a valve called the globe valves.
What is a globe valve?
The globe valve is a device that regulates the water flow in the pipes. You can notice a big steering wheel above a bump on the large water pipes, that wheel is the part of the valve. It is known as a hand wheel, which is attached to a disc. When you turn the handwheel, the disc moves, stopping or allowing the water to flow through the pipe.
Is a globe better than a gate?
A gate valve operates differently. It does not have a disc. Instead, it has a sort of barrier. When you turn the handwheel, it lifts it and allows the flow of the water. Due to this, leakage is common in the gate valve. However, it is not the case for the globe valves.
It is the right angle contact of the disc with the seat ring that prevents leakage. That angle allows the seat and the disc to be tightly sealed.
Can the disc be close in the direction of the flow?
Yes, the valve is mechanised to let the disc close against or in the similar direction of the water flow.
However, the disc should be closed in the direction of the water flow when there is a requirement of a quick-acting stop. On the other hand, it should be closed against the direction of the water flow when a quick-acting start is needed.
What are the parts of the valve?
When you are buying this valve, you should check that it has all the following parts present in it:
- Handwheel nut
- Handwheel
- Stem
- Yoke nut
- Stud bolts
- Nuts
- Gland flange
- Gland follower
- Packing
- Back seat
- Bonnet
- Bonnet gasket
- Disc nut
- Body seat ring
The body contains most of it, the handwheel remains on the top, poking out of the body. It is fixed in place with the disc through the stem, by the handwheel nut.
While buying the valve, do a thorough check to see if it is not missing any part. Also, ask the seller for a test run, so you can understand its function well.