Perfect Cure

Uncategorised,General

During a routine call to the Alexandra Hospital in Harlow, a chance comment from MSST John Allen led to an unusual installation for Pirtek Harlow.

He had merely asked if everything was OK on the site, and was consequently asked if he could fix a galvanised steel fuel pipeline that had sprung a leak. Quizzed if Pirtek handled fuel pipelines, Allen of course said yes, blissfully unaware of the true nature and size of the project at the time.

Up in the air

When he returned with the site manager to examine the defective pipe, John discovered it was in fact a 45 metre fuel line, and just to complicate things, it was 6 metres in the air.   This provided fuel for an emergency back-up generator to power the hospital in the event of a power failure.

The pipeline fed a 1,850 litre bunded diesel fuel tank that would provide power to the hospital for 48 hours.   However, because the existing galvanised steel pipe had failed, it was decided to replace the entire system rather than continue to repair it.

Original suggestion

After a lot of research and probing of the customer, an alternative system was suggested by Pirtek Harlow. This was a specialised long life, environmentally safe, two part Gemini UPP (Universal Petro pipe) fuel pipe supplied by Hytek.   The inner part of the pipe is made from low friction polyamide (nylon), which allows the small bore pipe to carry fuel at high velocity. The outer is manufactured from a puncture resistant polyethylene.

Specialised training

One small problem with using this system is that the joints have to be electrofusion welded.    Not something that is normally called for by Pirtek customers. Whilst the project was being carefully planned, specified and the quotation submitted, as this was a competitive pitch, two members of the Harlow Centre undertook a specialised training course organised by the manufacturer.

Each of the joints has a heating element that fuses each element of the pipe together when an electrical current is passed through the joint.   This means that the pipe has to be cut, hand scrived and cleaned before welding.   There is no room for error with the system and every joint had to be right or the entire pipe section would have to be replaced.

As an extra complication, the system cannot be welded in damp conditions and each of the joints takes 20 minutes to set.

When the contract was won by Pirtek Harlow, owner Perry Tubb and MSST John Allen set about installing the new pipework, which entailed installing tower scaffolding and moving and re-erecting the tower 11 times. Even this had complications as the hospital insisted the engineers had suitable PASMA qualifications for the tower work.

Alarming needs

Of course this wasn’t a case of just installing the replacement pipe. At each end, flow systems had to be installed, and in the back-up generator house, a leak detection alarm was fitted to ensure that in the case of a pipe failure, diesel would not escape from the system.   Two in-line duplex filters and a non-return valve were installed using 1″ 80 bar EN853 hydraulic hose, on a 1m2, 1″ board that entailed drilling through the walls to install.

The installation took 16 hours on the first day and a further 12 on the following day. Perry and Allen had to manhandle the 50 metre coil on to the roof of the main generator room where they discovered that the UPP remained its shape and wasn’t quite as supple as it was supposed to be. After wrestling with the coil, the first section was laid in place, and cut with a special cutter. Each joint was carefully marked and timed during welding.

Physical demands

Perry Tubb says that Hytex, with whom they have had a long-term working relationship, helped immensely with the welding equipment. When everything was finally in place, the entire system was pressure tested with Nitrogen to the manufacturer’s instructions. This was 40 percent of 3.5 bar for 30 minutes, increasing to 60 percent and finally 100 percent, of 30 minutes each.   Each of the two-part pipe system was tested in this manner.

The client then asked for the entire installation to be further protected from the elements with a neoprene outer coating. The neoprene has to be welded together using a white sprit solvent, an act that John Allen diplomatically described as incredibly messy.

However, the system passed all the tests and was commissioned two weeks later. “It was a very physical job, but the client was very pleased with the installation, in fact his exact words were ‘I’m chuffed to bits with this,” says Perry Tubb.   “A nice footnote to the job is that Pirtek Harlow are now featured on Hytek’s website as qualified installers of the UPP system.”