Rotalock dillema

[nike123]

I have one AC with two Rota-lock valves on hermetic compressor that has faulty HP/LP pressurestat.
I need to change that HP/LP pressurestat.
Its capillaries are connected at each rota-lock valves which have two ports. One port is near the stem of valve and other port is more in middle of valve. Capillaries are connected at that other port near middle of valve.

http://i50.tinypic.com/hwwnx0.jpg

From my memory this port cannot be closed by manipulating valve stem. It is always open to valve body.
What is easiest way to change that HP/LP pressurestat without carrying vacuum pump and recovery cylinders.
I need to do that job on some island and i wish to avoid excessive costs by transporting my van with ferry which is very expensive for me and my customer.

[B G Scott]

I have one AC with two Rota-lock valves on hermetic compressor that has faulty HP/LP pressurestat.
I need to change that HP/LP pressurestat.
Its capillaries are connected at each rota-lock valves which have two ports. One port is near the stem of valve and other port is more in middle of valve. Capillaries are connected at that other port near middle of valve.

http://i50.tinypic.com/hwwnx0.jpg

From my memory this port cannot be closed by manipulating valve stem. It is always open to valve body.
What is easiest way to change that HP/LP pressurestat without carrying vacuum pump and recovery cylinders.
I need to do that job on some island and i wish to avoid excessive costs by transporting my van with ferry which is very expensive for me and my customer.
Well if it is not leaking why don't you leave the old one in place and fit a new one to the guage port, which you can access by back seating it and fit a Tee fitting so you will still have the guage access.
Might not be the best asthetic result but it will avoid your costs.

[cool runings]

I have one AC with two Rota-lock valves on hermetic compressor that has faulty HP/LP pressurestat.
I need to change that HP/LP pressurestat.
Its capillaries are connected at each rota-lock valves which have two ports. One port is near the stem of valve and other port is more in middle of valve. Capillaries are connected at that other port near middle of valve.

http://i50.tinypic.com/hwwnx0.jpg

From my memory this port cannot be closed by manipulating valve stem. It is always open to valve body.
What is easiest way to change that HP/LP pressurestat without carrying vacuum pump and recovery cylinders.
I need to do that job on some island and i wish to avoid excessive costs by transporting my van with ferry which is very expensive for me and my customer.


You are correct.

So if you front seat the suction (wind it all the way in) and pump down the comp, then turn off the unit and front seat the discharge valve (again wind all the way in).

You have now isolated the comp from the system and you can change the hp / lp parts with little or no loss.

A quick vac of the comp will ensure it has no air inside (there will be little but a vac is best).

All the best

coolrunnings

.

[nike123]

Well if it is not leaking why don't you leave the old one in place and fit a new one to the guage port, which you can access by back seating it and fit a Tee fitting so you will still have the guage access.
Might not be the best asthetic result but it will avoid your costs.

That will be last option since old one is rusted and I am not confident that it will not leak soon.

[nike123]

You are correct.

So if you front seat the suction (wind it all the way in) and pump down the comp, then turn off the unit and front seat the discharge valve (again wind all the way in).

You have now isolated the comp from the system and you can change the hp / lp parts with little or no loss.

A quick vac of the comp will ensure it has no air inside (there will be little but a vac is best).

All the best

coolrunnings

.

Thanks, that was my preferred solution too.
Vacuuming is no option so careful pump down with little overpressure in suction will resolve issue with air. Than same thing on high side will keep air from entering. I will probably use plastic capillaries that will help quicker switching and minimal loss of refrigerant.

[B G Scott]

Well if it is not leaking why don't you leave the old one in place and fit a new one to the guage port, which you can access by back seating it and fit a Tee fitting so you will still have the guage access.
Might not be the best asthetic result but it will avoid your costs.
OK sorry about that but you did stress the financial issue more than the tech result.
I see more good advice coming from memebers that is what the site is all about

[nike123]

OK sorry about that but you did stress the financial issue more than the tech result.
I see more good advice coming from memebers that is what the site is all about


No need for apologies! Thanks for your input.

[lowcool]

sounds like you might as well bite the bullet now nike if the service valve is in bad repair.you could always walk onto the ferry with a wheelbarrow of tools and be picked up the other side
enjoy your get away and dont forget the fishing rod

[nike123]

Fortunately, ten years ago, when I commissioned that AC, i used 1/4" copper pipe to connect HP/LP pressurestat to rota-lock ports. Solution is so easy and I have it in my tool bag! Just needed some time to mature in my head!:D
http://www.yellowjacket.com/images/A_Wrnch/60661-66-and-60665.jpg

[lice to chill]

I"ve been known to change the bellows if you can find the same pstat.

[nike123]

I"ve been known to change the bellows if you can find the same pstat.
Sorry, I don't understand! I have same pstat but contact group does not function as supposed. I don't like to go there more than one time and I want to do that in first attempt.