What are the stainless steel valves processing 'coup' we don't know?
by:AIRWOLF2020-05-22
Stainless steel valves what we don't know processing & other;
Tips & throughout;
吗?
To the requirement of cutting stainless steel valve is leaking, the lower the better, soft seal valve leakage is the lowest, to cut off the effect of course good, but not wear-resisting, poor reliability.
From small leakage and sealing and reliable double standards, soft seal cutting is not as good as hard seal cut off.
As a fully functional ultra light regulator, sealed and pile has wear-resisting alloy protection, high reliability, the leakage rate of 10 -
7, have been able to meet the requirements of the cut-off valve.
Double seal valve why not as a shut-off valve use?
Two-seater valve core has the advantage of force balance structure, allow the pressure difference is big, but its disadvantage is that the two seal face not good contact at the same time, cause leakage.
If it artificially, mandatory used to cut off the occasion, obviously the result is bad, even made many improvements, for it is not desirable.
For single core stainless steel valve, when the medium is away, the valve has good stability;
When the medium is flow closed type, the stability of the valve.
Two-seater valve has two valve core, the valve core flow closed, valve core in the flow, so that when you are working in a small open degree, flow closed type of valve core is easy to cause the vibration of the valve, this is the reason why two-seat valves cannot be used for small open degree work.
For straight travel stainless steel valve throttling valve core is vertical, and medium level, cavity flow is bound to turn down turn, make valve flow becomes quite complex (
Shaped like fall & other;
S”
Type)
。
In this way, there is a lot of dead zone, provide the space for medium of precipitation, in the long term, causing congestion.
Quarter-turn valves throttling direction is horizontal, flow into the medium level, level, easy to take unclean medium, at the same time, simple flow, precipitation medium space is little, so quarter-turn valves prevent performance is good.
Straight stainless steel valve travel adjustment involves a simple mechanical principle: large sliding friction, rolling friction is small.
Straight trip valve stem up and down movement, packing a little pressure, it will wrapped the stem very tight, produce bigger return difference.
To this end, the valve stem design very tiny, packing and commonly used small friction coefficient of ptfe packing, in order to reduce the return difference, but the problem is sent stem thin, easy to bend, packing and short service life.
The best way to solve this problem, is to travel with rotary valve stem, namely quarter-turn class regulating valve, the valve lever than straight travel stem thick 2 -
Three times, and selects the long-life graphite packing, good stiffness, the stem packing long life, instead of the friction torque is small, poor little back.