Rules for hydrostatic strain testing have taken a big step ahead with the discharge of Water UK’s Water Trade Normal for hydrostatic strain testing of PE pipes, a transfer that may guarantee the security and reliability of the method, says Tony Kitchen of AHS Pipeline Innovation.
Water corporations and contractors are adjusting to the necessities of the brand new Water Trade Normal 4-01-03, launched in March 2024, which outlines the required requirements for the hydrostatic strain testing of polyethylene (PE) and polyethylene barrier pipes. The usual replaces earlier pointers from Info Steering Discover 4-01-03.
The transition from an Trade Steering Discover (IGN) to a Water Trade Normal (WIS) marks a shift in the direction of extra stringent and enforceable requirements that purpose to enhance the security and effectiveness of the strain testing course of.
WIS 4-01-03 specifies detailed procedures for strain testing below-ground water provide pipelines and sewer rising mains comprised of PE and PE barrier pipes. It contains pointers for testing whole programs in addition to alternative sections and repair connections.
The specs emphasise the significance of contemplating the viscoelastic properties of PE, which reveals what is called creep behaviour – deformation that happens when subjected to strain over time.
Understanding the distinction
You will need to perceive the distinctions between WIS and IGN:
● An Info Steering Discover serves as a set of suggestions or pointers that provide recommendation on greatest apply however doesn’t mandate particular actions or procedures.
● A Water Trade Normal is a extra formal doc that units out necessary necessities for merchandise, supplies or operational procedures. WIS paperwork are supposed to make sure uniformity and compliance throughout the water business, resulting in extra standardised and dependable outcomes.
Bettering security
The brand new WIS is designed to enhance each the accuracy and security of strain testing which suggests there’s now a zero-tolerance coverage on pre-pressurisation. Key factors are:
● The pipe have to be at ambient strain previous to testing
● If a take a look at has failed, the operator should go away the pipe for 4 occasions the size of the ramp-up time earlier than reattempting the take a look at
● The operators should wait for 2 to 3 hours between filling and pressurising the pipeline. This takes into consideration the results of thermal conditioning and permits the temperature of the pipe to stabilise as soon as it has been stuffed.
● The allowable air content material has now been decreased from 8 to 4 per cent
● The air content material should even be precisely calculated through the ‘ramp-up’ stage because the pipeline is dropped at system take a look at strain (STP). Which means that the take a look at may be instantly deserted whether it is over the appropriate restrict.
What WIS means for contractors
There isn’t a query that the brand new commonplace represents a big step in the direction of leak-free networks, however the brand new necessities probably impose a higher burden on contractors. The stringent guidelines round right preparation previous to testing, together with pre-pressurisation, thermal conditioning, and calculating air content material previous to beginning the take a look at, making it essential to get the take a look at proper first time, to forestall losing time and assets in retesting.
A discount within the allowable air content material means much less margin for error, which highlights, from a compliance and price perspective, the significance of contractors rigorously managing their very own and subcontracted pipeline strain testing.
As a result of growing complexity of hydrostatic strain testing and ranging ranges of experience amongst technicians and operators, some strain testing suppliers could not meet the requirements outlined within the WIS and will lack the data or expertise to appropriately put together the pipe for testing.
Contractors should be sure that all strain testing exercise is totally compliant with the brand new WIS specs. Substandard testing probably creates harmful conditions, with threat to life and limb, if air isn’t correctly faraway from the pipeline.
It’s essential for contractors to pick subcontractors with confirmed compliance to make sure the security and reliability of their initiatives if they’re to take care of each contractual obligations and a great repute within the business.
Confirmed experience
AHS Pipeline Innovation is recognised as an business chief in hydrostatic strain testing with over 20 years of expertise and nearly 50,000 assessments accomplished. The confirmed experience of AHS allowed the corporate to play a key function within the growth of the brand new WIS as a part of a multidisciplinary panel which included pipe producers, water firm representatives and commerce organisations.
Cautious consideration was given to onsite implementation of the brand new necessities, and the way contractors may be supported in assembly the usual.
Strain testing providers at AHS are already totally compliant with WIS 4-01-03 and incorporate the most recent know-how and real-time help from the corporate’s in-house analyst groups to provide contractors unrivalled assist all through the testing course of, guaranteeing that testing is true first-time.
AHS is supplied to information and assist groups in adopting these new requirements in order that their pipeline operations meet the mandatory necessities. Ought to water corporations and contractors be not sure about how WIS 4-01-03 impacts their operations, or require assist to make sure compliance, AHS is obtainable to supply the data and instruments essential to navigate this transition easily and successfully.
WIS 4-01-03 not solely mandates stricter controls over variables like air content material, ambient strain and temperature, it additionally successfully identifies and removes any actions undertaken onsite that may have an effect on take a look at efficiency. Importantly, it reintroduces guidelines that had been relaxed in earlier steerage, restoring rigorous requirements which can be important for sustaining the integrity of water programs and creating extra outlined regulatory expectations.
As well as, strain assessments carried out in accordance with the WIS are measured utilizing subtle algorithms that ship definitive take a look at outcomes, guaranteeing readability and reliability.
At a time when the water sector is experiencing reputational challenges, WIS 4-01-03 represents a chance for water corporations and contractors to get it proper from the beginning. By rigorously navigating these adjustments, and guaranteeing that each take a look at not solely meets however exceeds the most recent requirements for security and effectivity, they will mitigate threat to the general public and their very own groups altogether.
