Insulation of expansion valve

[davidr]

Evening all - I replaced the expansion valve in my 1989 V12 this weekend. There is a copper sensor coil that is connected to the bulb on the expansion valve. This is clamped to the outlet from the evaporator and is meant to feed back the temperature of the gas emerging from the evaporator in the cabin so the expansion valve opens and closes accordingly.
To ensure that it measures that output temperature and is not affected by the ambient temperature of the engine bay it is insulated.
I had to remove the insulation to install the new expansion valve and I'm not sure what to replace it with. Anyone got any ideas?

[Brakebuster]

hmm

i too have to insulate this part

i will put on my thinking cap ,


BB

[davidr]

Hi BB - I guess it needs to be something that gives good thermal insulation and is heat resistant. I don't know if there's some kind of foam in a can?
I had considered using silicon rubber but I'm not sure how well that keeps the heat out.

[ptjs1]

David,

Could you cut a small piece (or two) of standard closed cell grey foam pipe lagging and then tie wrap it around the valve? Cheap to buy from B&Q or similar.

Paul

[davidr]

Hi Paul - I had considered that but it's not a straight forward shape. Previous stuff used was a gooey sticky substance which I guess was original.

[poprivet]

It seems to be a Self-Amalgamating putty or duct putty.

I think its more for holding things in place and sealing up the gaps more then purely insulating. I've seen similar stuff used by electricians to seal cable going through bulkheads.

[Brakebuster]

ah , if its what we call ' brown ' its as pop describes, though does not have ' insulating properties ' that I am aware of

I have some already , and can bring it along to Kemble

BB

[davidr]

This is the kind of thing I'm talking about. Lifted this image from Google - not sure what car it is - probably not even a Jag but it does show the gooey stuff used for insulation.