Author Topic: Globe valve and Handwheels  (Read 31093 times)

Offline vcutajar

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Re: Globe valve and Handwheels
« Reply #60 on: December 08, 2014, 05:20:20 AM »
Thanks Don.

Vince

Offline sshire

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Re: Globe valve and Handwheels
« Reply #61 on: December 08, 2014, 01:35:55 PM »
Simon
Not sure how I missed all of the fun here but, this thread (and your valves) must be a keeper. A wonderful class on globe valve making.
Love it.
Best,
Stan

Offline Dan Rowe

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Re: Globe valve and Handwheels
« Reply #62 on: December 08, 2014, 04:59:11 PM »
I know this thread is a bit old, but I am reviving it because I have a question I would like to ask.

In my search for a simple valve to make for my current project I came across a diagram that Tel posted on page two of this thread.

In this diagram which I am reattaching, which is the inlet and which is the outlet?

Vince,
The rule of thumb for a globe valve is the gland is on the outlet side of the valve. This is done so when the valve is shut off the gland packing is not under pressure. See the diagram in post 15 to see the usual arrangement of a globe valve.

Dan
ShaylocoDan

Offline vcutajar

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Re: Globe valve and Handwheels
« Reply #63 on: December 08, 2014, 08:56:58 PM »
Thanks Dan.  I see what you mean.

Vince

Offline Dan Rowe

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Re: Globe valve
« Reply #64 on: December 08, 2014, 11:14:29 PM »
Vince, Looking at the drawing provided by Simon in post 15 shown here:



There are two valves made to the same pattern. If the stem is the same part as the disk or if they are fixed together it is a stop valve.

If the disk is not fixed to the stem and the stem only acts as a guide to center the disk then the valve is a stop check valve and it will only open if the inlet pressure is higher than the outlet and of course the stem is in the up position. The stem can only shut the valve.

The only way to tell the difference between a stop valve and a stop check valve is to look inside and check if the disk is fixed to the stem. The casting on a full size valve will have an arrow but it points the same direction on both types of valves.

On the ships we usually had a bucket of valves that needed repair. It was always the job left for when there was nothing pressing to do.

Dan
ShaylocoDan

Offline derekwarner

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Re: Globe valve and Handwheels
« Reply #65 on: December 09, 2014, 12:27:35 AM »
Another point here for model valves is if the constrained disc floats on the stem.....then the degree of alignment is not as critical

I purchased a 1/8" steam stop valve from a reputable British manufacturer which leaked steam @ 3 Bar...inspection confirmed a one piece stem/disc construction but with some eccentricity as the disc confirmed only approx. 75% witness marking....... :facepalm:

The manufactured protested this could not happen  :Director:.......however finally provided a FOC replacement valve [& a few fittings to boot] after digital images were offered & the return of the valve from OZ to UK...as the return APP cost back to UK was approx. 33% the cost of the valve........ Derek
Derek L Warner - Honorary Secretary [Retired]
Illawarra Live Steamers Co-op - Australia
www.ils.org.au

Offline Don1966

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Re: Globe valve and Handwheels
« Reply #66 on: December 09, 2014, 12:53:11 AM »
Dan appreciate you clearing that up and thanks for the diagram.

Don

 

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