big servicing job to quote

[mike_s]

Fitted a boiler in an engineering workshop today. Next week they are showing me around properly to quote on the annual servicing of their industrial heaters. They provide scissor lift and just arn't too keen on their usual firm.

It is around 11-13 various industrial gas heaters. Mostly radiant tube heaters and warm air blowing unit heaters.

it is a large gas system, mostly 3 and 4 inch in diameter and could be 100M in length. There are sectional isolation valves with around 1 inch pipework to each heater but I have my commercial testing and purging ticket with all these appliances anyway.

I will research with the manufacturers regarding the servicing procedure but if anybody wants to give advice or tips that's great. They say some of the heaters arn't working properly and sounds like the fan bearings are going. I'm not very experienced with these so hope I don't over or under price it. The guy who passed me the job has a large maintenance contract with the local factories so I'm starting to go around all of these which is very exciting.

I'm thinking it should take a couple of days to service all of these?

Also, when doing an annual service and safety certificate on a place like this, do you just service and test from the sectional isolation valves or de-pressurize, test and purge the whole lot? I will try to find out what they are expecting but do you do the full tightness test from and meter and purge of the entire system on an annual service and safety certificate? Am I required to do this for an annual commercial safety certificate?

They say it takes a full day to purge the system, I have to measure the installation volume and calculate the purge first as well which is a few hours.

I'm looking at another factory next week too so I really need to find out how far to go with this as I don't want to price my self out but I also want to do a proper job.

 

[Scott_D]

Test as an existing system?
Shouldnt be any need to purge unless you are adding air.

 

[Dotty]

Why are you wanting to purge the system? Strength testing only needs doing on new pipework or new extensions. A tightness test will suffice. Even using a j gauge there's unlikely to be any need to section the pipework (100m of 4" = 0.009 x 100 x 42 x 1 x 0.047 = 1.78 minutes)

A system that size will most likely have a rotary meter. Don't include the rotary meter in your calculations. The let by test will most likely trip the slamshut. You can't reset the slamshut. Valve off at the ecv immediately after the meter.

Do you have your ipaf license for driving the scissor lift?

Don't forget you're only quoting for the service work, any and all faults you find are remedials and should be quoted for separately.

 

[mike_s]

I don't have this license so I will have to get it especially as they are strict on health and safety so I'm sure they will check I have this anyway.

I'm asking about the purge as arn't you supposed to purge each time the system is de-pressurized, even if it is just the ecv turned off for a tightness test? Or is this only when the pipework is cut open? They will probably want a tightness test from the meter to cover the whole lot. So the tightness test = only 1.78 minutes? I thought it would be 30 minutes with a u gauge? What's a j gauge? They are on the ball, they used to have a solenoid for the fire alarm system which they took out as each time it went off they got someone in to do a full purge taking a full day? Maybe I have got it wrong that it needs purging every time the gas goes off then. Obviously a tightness test should suffice seeing as I'm not altering the gas pipework but do the regulations back this up? I was going to Pm you over this Croppie but hoped you would reply here, thanks!

Also regarding the slam shut valve, to prevent this do I only turn off the ECV at the meter outlet? Sounds similar to when I worked on medium pressure recently.

 

[tamz]

You don't need to depressurise it to service an appliance and you don't really want to. Shut it off from the appliance valve do your work and soapy the connection you split. That is all you "need" to do but John will keep you right as i'm out this for a wee while now. (maybe i should get back into it and my wee woman is all pasma'd up so she could drive a scaffold :lol: I'll need to ask her if she can drive a scissor lift !)
A J guage is directly under a U. Whisky blurrs the vision
Have you got a copy of UP1? Pm me your email if you want a copy

 

[tamz]

Turn it off at the outlet. Saves you breaking the law.

 

[Dotty]

There should be an ecv immediately after the meter, just test the pipework and appliances. You only need to degas the pipework in the event of alterations where you're cutting ang altering the pipework.

Rather than remove the safety solenoid a fire alarm override panel could've been installed to prevent the gas panel going into alarm when the fire alarm is tested.

A j gauge is a high sg fluid gauge. Regin do a nice one.

Pm me whenever you want Mike.

 

[tamz]

Do you not use an electronic john or don't you trust them?
Personally i don't.

 

[Dotty]

I use electronic for setting up burners and my j gauge for tightness testing. No particular reason other than I'm old school too.

 

[Dotty]

Sometimes I think it's the look of the thing Tam. An electronic gauge doesn't have the same mysticism as a water gauge.

 

[tamz]

Pretty much the same. A real gauge never lies.

 

[tamz]

Sometimes I think it's the look of the thing Tam. An electronic gauge doesn't have the same mysticism as a water gauge.

Especially when the water is blue :lol:

 

[mike_s]

Cheers, yes I've got a copy of up1, and 1a. Cheers for the heads up on not turning off the meter inlet valve. I will look into them J gauges. Are the calculations for using a J gauge in either up 1 or 1 a? There doesn't seem to be many sectional isolation valves although I think each appliance has their own. Do you have to do do a full tightness test on the whole system for an annual safety certificate then? This may be an obvious yes but I don't think they will want it all turning off at once for a test, I may have to do it at night or over the weekend. I forgot to mention there is a big boiler somewhere too. I only fitted a domestic one in the office today. The more I think the more I'm sure it is a couple of days work for a proper job so I hope they are expecting me to allow for this in the quote.

 

[Dotty]

Would actually be less disruptive testing the whole installation in one go. Quicker too.

And it's the meter OUTLET valve.

 

[mike_s]

Cheers, yes that's what I meant, I'll test from the meter outlet valve to end of the gas run. Also when was larger than 2 inch steel gas pipe last allowed to be screwed? I know current regulations say anything bigger than 2 inch must be welded or is there an exception? I think they said they had some people in the other week doing alterations and they were screwing 4 inch...

 

[tamz]

Using a high specific gravity gauge is where John got the 1 in his calculation. That is the GRM. A water gauge is 0.5 and an electronic 0.1. It is all in UP1. You need to learn it. Btw you round the time up.
If you are pricing for purely servicing look up the manu's on the types of heaters and decide how long you think to do the service. Don't try second guessing anything that is wrong with them. That is a separate chargable item whatever you find.
Not sure about the tightness test on a safety cert as all this stuff wasn't bothered with when i was doing it but i would think yes it would need it. Any interruptions are minimal but allow time to go around the place telling them its going off then the time for relighting.
They are used to being charged (ripped) a day for a slam shut going down so charge it accordingly for a test (you don't need to purge).
Don't undersell yourself. You can get good money for this type work.

Btw you sound a bit green on this so ask as much as you feel. We all had to learn. Its better if you can get hold of someone who is used to this type work to tag along for a reasonable fee. You will learn more over a couple of days than you ever will in some acs class.

 

[tamz]

I think it is about 4 or 5 years ago they changed the rules to 2" but i'm not sure if repairs would need to be welded?? certainly new stuff should.

 

[Dotty]

Can't remember when the regs changed regarding screwing/welding. It's ncs at most if it passes tt. If it doesn't pass tt then raise merry hell.

Just make sure you have it noted. And if you find out the company who did the alterations is, give them a call and remind them. May get somewhere, may not.

 

[Scott_D]

A couple of agency guys who have never been GSR were talking about a 4" screwed gas run they had just finished.
Someone turned up to test it but refused as it wasn't welded.
They got sacked but were on another job by the next day.

 

[Dotty]

A couple of agency guys who have never been GSR were talking about a 4" screwed gas run they had just finished.
Someone turned up to test it but refused as it wasn't welded.
They got sacked but were on another job by the next day.

Sounds about right. Had an argument about this with one of our contract managers a couple of year ago. even when I showed him UP/1 he wouldn't have it.

I did win in the end when one of the directors heard and knew I was serious about riddoring my own company!

 

[mike_s]

So it seems common that people try to get away with screwing bigger than 2 inch. I will find out when the last alterations were done. Yes tamz i am green on this but really want to get into it so i really appreciate tips off u guys. I am picking up quite a bit of commercial work, more than i expected since doing my change over. I think it is vital for my company. I have all related british standards and igem documents printed out.

 

[mike_s]

Sorry forgot to say, is there still a risk of the slam shut valve going off even if im only testing from the meter outlet? How should i prevent it?

 

[Scott_D]

I think people who dont know what they are doing or cant weld will try and do it an easier way.
You can use 4" stainless steel mapress for gas, must get gas fittings though.

 

[on31ll]

I think people who dont know what they are doing or cant weld will try and do it an easier way.
You can use 4" stainless steel mapress for gas, must get gas fittings though.

I thought mapress was only upto 54mm and under a certain pressure ?

 

[Scott_D]

You can use copper Mapress with gas fittings up to 54mm
Stainless steel up to 108mm
Not sure if it has pressure limitations, I only do low pressure work.