Sip Airmate does not cut out at pressure

[Stephen S]

I've got a Sip Airmate T1.5, 25ltr tank. The issue I have is that the compressor more often than not keeps compressing, without cutting out, and consequently blows the air pressure safety valve.

The valve tends to let go at around 9 - 9.5 bar, and on occasion the pressure switch cuts in as it should at around 10 bar. My understanding is that this is a 12 bar rated unit, so unsure why it's not reaching that, and why I have these issues.

Can anyone help me identify the fault? Any help would be much appreciated, many thanks.

 

[the snooper]

Remove the top of the switch there will be a nut or a screw there back it off until it cuts out at the desired pressure if it doesn't work you may need a new switch, adjusting it may correct the fault depending on what the problem is but it's worth a go

 

[dobbslc]

I had the same on my old Clarke compressor and fiddling with the settings did nothing, I just replace the pressure switch for about £16 and it was fine after. I think they are set to 9-10 bar standard, the tank is obviously overrated higher to stop it exploding!

 

[pedrobedro]

My understanding is that this is a 12 bar rated unit, so unsure why it's not reaching that, and why I have these issues.

Can anyone help me identify the fault? Any help would be much appreciated, many thanks.

12 bar would be 180 psi I don't think any home user compressor is rated that high, 120 to 150 probably. Have you tried altering the cutout screw like Snooper says it might just need reseating but as dobbs says a new switch is not too expensive and would be safer than letting it blow the valve.

 

[rtbcomp]

It's more likely 10bar than 12 as pedro says. If it's cutting out at the right pressure then the pressure switch is OK. If it's blowing off at below the right pressure then the spring in the safety valve is weak. Some safety valves are adjustable, but generally speaking they come in 9 and 11 bar fixed ratings so you choose the one rated at 1 bar above your cut-off pressure.

 

[AdrianH]

I have looked at the SIP Airmate site and many are 8 bar units there are a few at 10Bar for the direct drive jobs and these are

SIP Airmate TN1.5/25-O Oil Free Air Compressor
SIP Airmate OL197/10RC ProTech Air Compressor 110v
SIP Airmate TN 3/50-D Oil Lubricated Air Compressor 14 CFM
SIP Airmate F1 260/50 ProTech Air Compressor
SIP Airmate TN3/100-D Oil Lubricated Air Compressor
SIP Airmate OM250/50 ProTech Air Compressor -110v

If the safety valve is blowing at 9 to 9.5 bar might I suggest that the safety is OK just needs a new cut off switch?

Trying to think if mine has a plate saying what the working pressure is, but I'm not going to the garage tonight, to cold.

Adrian

 

[Stephen S]

Thanks all for the ideas and views. I'll give the switch tweak a go and see if this helps, as by the sounds of things, the pressure relief valve is working as it should. I'll let you know how it goes, and fingers crossed because I think the replacement switch unit is over £40 from SIP.

 

[the snooper]

Thanks all for the ideas and views. I'll give the switch tweak a go and see if this helps, as by the sounds of things, the pressure relief valve is working as it should. I'll let you know how it goes, and fingers crossed because I think the replacement switch unit is over £40 from SIP.

they can be had a lot cheaper just make sure the one you get has enough ports on it

 

[dobbslc]

You don't have to buy a SIP one!
Just get one with the correct pressure rating from eBay.
Use ptfe tape on all the threads and you'll be ok.

 

[Stephen S]

Ah, right, I see; great tip and appreciated, I'll have a look for one on eBay and see what I can come up with. Thanks again.

 

[brightspark]

here http://www.ebay.co.uk/sch/i.html?_f...RS0&_nkw=compressor+pressure+switch+&_sacat=0

 

[Stephen S]

Thanks for the link brightspark, bound to be one for mine in there somewhere and at least half the price! That's great, thanks again.

 

[Stephen S]

I wanted to give a quick update; when I was looking at how to remove the pressure switch I found the adjustment screw for the cut off pressure setting as described by the snooper. I backed this off about half a turn and hey presto, problem solved! The pump now stops dead on 8 bar which coincidentally lines up with a previously unnoticed red line on the gauge. Chuffed I don't have to worry about replacing the switch, plus I've found out a little more on how the unit works. Thanks again to everyone for your help.

 

[rtbcomp]

Nice one. Normally the adjustment doesn't give rise to the intermittent symptoms you described, but if it's fixed all well and good. I'd keep a weather eye on it for a while just in case.