29 mb when doing tightmess test

[grill]

Hi again guys,

Was servicing a boiler this evening and got to the job and started my usual routine. (s usual as it gets seeing as im only a newbie.)Anyway i did my let by test and everything was fine then went on to do my tightness test. I slowly tweaked the pressure up and i had 29 mb reading. Tightness test was successful

Working pressure etc was all within acceptable range for the boiler. Should this have given me cause for concern? Is this a governor problem?? Should i contact the gas company (Pheonix Natural gas Belfast)?

Any thoughts would be greatly appreciated. This site is becoming very addictive!!!!

Grill.

 

[gasright]

isn't a tightness test done at 20mb.

Thats what i've been taught anyway

 

[clf-gas]

Tightness test is at 20mb, gas sound at 29mb could this lead to governor lockup

If its not out of your way nip back tomorrow and test again at 20mb, piece of mind for you Grill

 

[namsag]

Not unusual to get that amount but you should have turned main tap off when it got to 20mb by testing at that pressure you may have locked up the governor and not tested from there to the main tap. Basic

 

[grill]

Cheers guys,

Ill nip back and check.

grill

 

[meldrew's_mate]

Recheck working pressure at meter tapping point with the boiler running, if it's over 22mB contact Transco (or your gas transporter if different in NI, perhaps Phoenix?) to get the regulator looked at, unfortunately that means turning off the gas supply until they arrive (usually pretty quick) which some customers moan about, it could be classified as ID (no meter regulation).

I assume it is NG, not LPG???

 

[ChrisR]

The spec is 21mb + or - 2 mbar.

 

[gas4you]

Excellent chris, nice to see someone who knows new working pressure parameters

 

[Gasguru]

Oh dear, such basic procedures and not a clue is there any hope for the industry.

 

[Slugbabydotcom]

Tightness test is at 21 mb. Governor locks out at about 25mb

Your successful tightness test @ 29mb did not include the small part of the system between the ECV and the locked up governor.

You can get higher static readings when the gas rushes through at the start of a test. 29 mb is not uncommon. Let the gas out and start again whenever you let the pressure go over 25mb. Sometimes even higher readings can be got by opening the ECV too quickly and the water can be lost from your guage.

The 21mb is actually a working pressure [with appliances in use] + or -2mb as ChrisR said

 

[namsag]

Slug where do you get thefigure 21mbar as your tightness test from

 

[gasright]

Tightness test is at 21 mb. Governor locks out at about 25mb

Your successful tightness test @ 29mb did not include the small part of the system between the ECV and the locked up governor.

You can get higher static readings when the gas rushes through at the start of a test. 29 mb is not uncommon. Let the gas out and start again whenever you let the pressure go over 25mb. Sometimes even higher readings can be got by opening the ECV too quickly and the water can be lost from your guage.

The 21mb is actually a working pressure [with appliances in use] + or -2mb as ChrisR said

Sorry but according to the CCN1 test paper and my Corgi inspector a tightness test is at 20mb and let-by at 10mb

 

[bripl]

just a couple of points 29mb is not unusual in belfast we have low pressure and medium pressure

your test depends on type of supply low pressure is 20mb
medium pressure is 16 let by 10 let by and test at 20mb,two let by tests on medium ecv and governor then tightness at 20mb,hope this helps.grill you need to contact phoenix about this and they will do dam all as is the norm the book says 20mb but the training centre wants you to test at 19

 

[scatmanjohn]

new working pressure parameters

3 years is not exactly new.

grill wrote:

Should this have given me cause for concern

No, but your lack of understanding off the tightness test is.

Just out of interest, do you know why a let by test is carried out?

 

[baxpoti]

According to Viper Gas and my ACS 6 months ago.

Low pressure tightness testing is carried out at 20mbar.

Governors are adjusted to give a working pressure at the meter outlet between 19 - 23 mbars.