Danfoss RAS-C2 gland replacement - quick question

[simonhill]

Hi guys. Very specific question...

Got a RAS-C2 where the pin will only move a fraction of a mil and no amount of the usual tapping/WD40 will help. So looking to change the gland rather than the whole TRV.

Has anyone here changed a RAS-C2 gland before? There doesn't seem to be anything to grip to support the setting ring when turning the nut. Hope that makes sense - the setting ring is the plastic cover with arrow on it that you turn to select the direction of flow. If you don't support it and apply pressure when unscrewing the gland nut, you end up turning the setting ring anti-clockwise and then once it stops, you're applying pressure to that mechanism. You can't grip the setting ring as it's plastic and even if you pop off the plastic cover, the metal underneath is just serrated and doesn't grip. The nut is going to need a really good pull to get it to undo and I don't want to put all that pressure on the setting ring.

I appreciate I could just change the whole valve, but don't really want to do that if not necessary.

 

[ShaunCorbs]

Yes you can you can even do it live if you have there tool

When it’s drained it’s the brass hex you need to undo right at the end

The plastic should come off

 

[simonhill]

Yes you can you can even do it live if you have there tool

When it’s drained it’s the brass hex you need to undo right at the end

The plastic should come off

Hi Shaun,

Thanks. Yes, I know it can be done live - one of the goods things about the RAS-C2. And I know it's the brass hex. But when you turn the brass hex, it also turns the setting ring that sets the valve direction. Then the setting ring hits its maximum anticlockwise limit and so when you apply further pressure to undo the brass hex, you're forcing the setting ring past its limit which can't be good for it. You can't grip the setting ring to stop it turning (even with the plastic cover off) because it's just serrated rather than being a nut/hex.

A problem here is that the reason for changing the gland is that the pin barely moves because it's crusted up with corrosion. I imagine the hex nut is difficult to shift for the same reason so will need a lot of force to un-crack it. Do you think it's ok to force this?

 

[Basher]

Hi Shaun,

Thanks. Yes, I know it can be done live - one of the goods things about the RAS-C2. And I know it's the brass hex. But when you turn the brass hex, it also turns the setting ring that sets the valve direction. Then the setting ring hits its maximum anticlockwise limit and so when you apply further pressure to undo the brass hex, you're forcing the setting ring past its limit which can't be good for it. You can't grip the setting ring to stop it turning (even with the plastic cover off) because it's just serrated rather than being a nut/hex.

A problem here is that the reason for changing the gland is that the pin barely moves because it's crusted up with corrosion. I imagine the hex nut is difficult to shift for the same reason so will need a lot of force to un-crack it. Do you think it's ok to force this?

Does this help? - guess you may have this already. The setting ring comes off!

https://www.plumbworld.co.uk/documents/danfoss-ras-c2-bi-directional-radiator-valve-installation-guide-013g605500.pdf

 

[simonhill]

Does this help? - guess you may have this already. The setting ring comes off!

Hi Basher, thanks, yes already have this. Taking the plastic setting ring off doesn't help as there's just serrated metal underneath that you can't get a grip on.

 

[ShaunCorbs]

I always just grip the serrations as tbh once set eg flow they don’t do much bet you danfoss sell a spanner for that

 

[simonhill]

I always just grip the serrations as tbh once set eg flow they don’t do much bet you danfoss sell a spanner for that

Great - thanks. Will try that and will give Danfoss a call to see if there's a spanner.