Valve stiff under Pressure?

[Segs14]

I am beginning to think that it may be a bad kit or the wrong kit. I measured the hps with a caliper and it appears to be a bit wider in diameter that the old one. It could be that was the way it was made or the old one had worn down and that is the reason for the reduced diameter.

 

[captain]

Valves can last 20 or more years with no service. If you can turn it on and off reasonably easy and it doesn't leak there is no need to do anything to it other than perhaps change the bust disc every 5 years at hydro. I have 50 year valves with their original parts that are fine. I have taken them apart and cleaned and lubricated them but never replaced anything.

 

[widget]

I am beginning to think that it may be a bad kit or the wrong kit. I measured the hps with a caliper and it appears to be a bit wider in diameter that the old one. It could be that was the way it was made or the old one had worn down and that is the reason for the reduced diameter.

I would say, thats your problem right there.!

Spindles / seats dont wear down, as Captain says valve parts dont really wear in any noticable manner, the nylon face of the valve seat will over time form an indentation and eventually leak, but the most common cause of valve failure is dirt and corrosion and manual overtightening of the hand wheel, which puts excessive pressure on the seat and knife edge and stresses the spindle.

 

[JeffG]

What would cause this?

The manifold could be out of alignment. (very slightly)