Hopkinson Parallel Slide Valves

......and the reason the manufacturer can't be contacted directly is what, please?

I think Hopkinson were taken over by Weir a few years ago. Try their website

Thanks I will give Weir a try.

I was unable to find any thing on the Weir site do you have any other ideas?

Also i would like info on blueing and lapping the valves?

Try this then go to their service centres.

weirpowerindustrial.com

I would suggest you are very careful as Hopkisons are a very high integrity valve and the lapping and matching of gate seats is very high precision. Even Weirs themselves sometimes have difficulty meeting the required finish (I have come across a case where the Hopkinson factory spent months getting the seal lapped properly on a 10" ball valve).

There are other people who do high integrity gate valves and their service centres would probably be able to carry out the work for you. If you are able to do it yourself you are probably among the highest skilled people in the world in this field.

I have 16 12" hopkinson parrellel slide valves to referbish and i basically need as much information and ilistrations for my crew to be able to ready over and get to know the valve inside out. I am also going to need the finish the valve requires?

The valve seats are lapped. I am not an expert on flat plate lapping but for the valves, obviously the better the finish, the better the seal. Again, it is worth discussing the grade of lap abrasive with one of the parallel gate valve manufacturer service departments or a workshop that specialises in lapping of valve seats.

I have looked at the Weir site and they have a pdf that gives some background on these valves. The document is -

http://www.weirpowerindustrial.com/products__services/valve_products/gate__globe_valves/hop_-_wedge_gate_valves.aspx

Hope this assists.

Thanks

I found that site, it has some good info but if you come across any more i would appreciate if you could let me know.

I used to be a site service engineer for Hopkinson vaves at Huddersfield travelling all over before Weirs got there hands on them. I have supervised Shutdown overhauls on various Power Stations working on main Stops Safety valves Torsion Bar type. Reference the Finish for the P/Slide Valves if they are on steam the lapping is easy and does not require a polished finish 360 fine Carbarundum paste would be good enough.,If you require any info please email me I may be able to help stuartson2004@yahoo.co.uk