Would you stay in a house with strong walls but a weak door?
If thieves are able to take your valuables away from the doors, it renders the strong walls of the house useless.
Packings in valves work similarly to a door
It allows the stem of the valve to move smoothly and interact with the media but prevents the media from going outside. It is important that the packings remain intact. However, a number of factors damage the packings and ultimately threaten to reduce the life of the valve.
These are 5 major threats that weaken and damage your valve packing:
Choosing the right packing material is key to the durability of the valve. If the packing material is not resistant to the chemical composition and temperature of the media, thermal cycling could severely damage the seal. The seal made of Teflon has a much higher expansion point than that of steel, which comprises the rest of the valve. Due to the heat, the packings expand and contract rapidly and thus wear out.
Vibration induced by the flow of media and many other factors is present to some degree or other in the case of a control valve. Vibrations can often lead to the friction of the packings, causing it to wear out before time.
Lack of maintenance
Lack of proper maintenance could only be the most serious threat to the life of your valve. It is advised that packings should be changed every 2-3 years even if there is no leakage or damage. Many times, it is thought that putting more number of packing rings will offer better protection from leakage. However, it could lead to more problems instead. Packings will consolidate with time, and with more rings, you will need to adjust the packings more frequently.
Wear and tear
Time is the greatest enemy of valve packings. As the packings become older, they will be affected by factors such as process temperature, ambient temperature and even seasonal changes. The packings will loosen up. In the beginning, when the leak is small, tightening the screws around the packings might work. However, for a more reliable solution to the problem, it is wise to replace the packings as they begin to wear out.
If the packings are not installed correctly, it will disturb the distribution of load. Improper installation of packings causes considerable leakage in high-pressure valves. Many times, repairmen make do with just the estimation of gland torque after installing the packings. Instead, it is wise to check and ensure the correct torque. The wrong installation also leads to improper compression of the packings. This means either an insufficient load or excessive load, which leads to leakage or reduces the life of packings respectively.
Also, the excessive load on packings will increase the torque of the valve leading to a separate set of problems.
Packings are a vital part of a valve. It can also be damaged if the valve is stored in a humid place without use for a long time. In order to avoid this from happening, you need to put the valves to use as soon as they are delivered. At IPC, our core goal is to deliver the best quality valves in shortest possible lead time so that you can put them to use as quickly as possible. If you need durable and reliable valves in a short lead time, drop us a mail at firstname.lastname@example.org or call on +91 (020) 6630 4580 / 6630 4583