Key factors that influence the service life PE pipe

There are many factors that can influence the lifetime of PE pipe. Typically polyethylene pipe can last between 50-100 years if designed, maintained and installed correctly. We take a look at the top five considerations when designing and installing PE pipe in order to achieve a long service life.

Operating conditions
Operating conditions including temperature, pressure and even weather conditions can affect the overall quality of a joint. PE pipes may be used at operating temperatures between -40°C and +80°C. For temperatures less than 20°C it is conventional to use the 20°C hydrostatic design stress. Below freezing, additional care may be required as the impact strength of PE is reduced. Adjusting temperatures to suit the operating conditions can extend service life to beyond the nominal 50 years.

High and low temperatures can affect the quality of the pipe but weather conditions must also be considered. During heavy rainfall, it’s important to remember that when fusion welding polyethylene pipe that no water or moisture is present in the fusion zones. The presence of water or moisture on pipe and fittings when welding can cause catastrophic joint failure when the system is under operating pressures. It’s always critical to adhere to best practices and consider weather conditions and prepare accordingly with the correct equipment and shelters.

Material
Material quality is a core factor of PE pipe service life. Polyethylene pipe boasts significant material benefits over traditional materials such as metal or concrete. High-Density Polyethylene Pipe (HDPE) is a thermoplastic pipe made from material that is flexible, durable and has outstanding levels of crack resistance. As HDPE is highly flexible, the material offers an ideal solution as it is unaffected by ground movement and therefore does not carry the same risk of splitting, cracking or corrosion as traditional alternatives. Of course with any product, the quality of the raw materials used and the manufacturing methods can affect the finished product. Peak prides itself on manufacturing PE pipe using the highest grades of material and thorough testing methods. HDPE can also be recycled at the end of its life cycle, and although this doesn’t affect its service life, environmentally, it’s a great solution and can be processed into other polyethylene products.

External pipe loading
All buried pipelines are exposed to various conditions which may affect the operation performance and life of the product. Things to be considered when designing a buried system are bedding and sidefill requirements. Guidance is provided on the selection and use of materials suitable for providing structural support to buried pipelines in IGN 4-08-01 (Bedding and Sidefill Materials for Buried Pipelines) and WIS 4-08-02 (Specification for Bedding and Sidefill Materials for Buried Pipelines). Trench depth and width will also considerably affect the loading on the pipe. The normal minimum depth of cover for mains should be a minimum of 900mm from ground level to the crown of the pipe. The width of the trench should be no less than the outside diameter of the pipe plus 250mm to allow for adequate compaction of sidefill unless specialised narrow trenching techniques are used.

The surrounding environment
Chemical loading can also affect PE pipe service life including risks from contaminated soils, for example. In addition to this, it’s crucial to consider the placement of the pipe if it is near tank stations where gasoline and other oil products are stored. Leakage of these into the soil over long periods may affect the performance of PE pipe.

PE jointing installation

Installation methods
Installation methods and carrying out correct installation is one of the most important factors when influencing the life cycle of any PE pipe. PE pipe can be welded between temperatures of -30°C to +50°C. As the weather changes and the temperature gets colder it’s important to take extra care when welding with electrofusion fittings, having the correct tooling can ensure the process is carried out effectively. Preparation of the pipe is also key on installation, PE pipes can become a lot firmer and less rigid in cold temperatures so preparation is key before carrying out a weld. It may take extra time to scrape and prepare the pipe but with the correct tooling and patience, you can ensure a good quality joint, even in minus temperatures!

References

ISO 1167-1:2006
Thermoplastics pipes, fittings and assemblies for the conveyance of fluids – Determination of the resistance to internal pressure – Part 1: General method

ISO 1167-2:2006
Thermoplastics pipes, fittings and assemblies for the conveyance of fluids – Determination of the resistance to internal pressure – Part 2: Preparation of pipe test pieces.

ISO 9080:2003
Plastic piping and ducting systems – Determination of the long-term hydrostatic strength of thermoplastic materials in pipe form by extrapolation.

ISO 13761:1996
Plastics pipes and fittings – Pressure reduction factors for polyethylene pipeline systems for use at temperatures above 20° C.

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Peak provides innovative ClearDuct™ pipe to the world’s largest offshore wind farm

Offshore windfarm

Hornsea Project TWO chose Peak Pipe Systems innovative ClearDuct HDPE electrical cable ducting for the second phase of the world largest offshore wind farm. Located off the Lincolnshire coast in the East of England, the project consists of over 400 wind turbines, covering more than 1,564 square kilometres off the North Sea and is the world’s largest offshore wind farm, providing low carbon power to over one million homes.

Ensuring the safe and effective transmission of the wind turbines generated electricity was a key part of the project’s delivery. Peak’s innovative ClearDuct was an ideal choice for the host conduit duct to house and protect the multi-million-pound high voltage cables which carry the electricity generated by the colossal turbines that is transmitted to the national grid.

ClearDuct Pipe

Over 50 kilometres of Peak’s ClearDuct HDPE electrical cable ducting was supplied throughout the project. ClearDuct has a unique design that ensures a damage-free solution to the cable and eliminates the potential for overheating. The unique machined pipe end design means that the internal fusion bead which is created during the high integrity welding process is recessed into the pipe wall, unlike conventional butt fusion welding. This guarantees no protrusion of the bead into the internal bore of the pipe, leaving cables with an unobstructed insertion path and no potential snagging points. Peak have created bespoke welding parameters which resulted in more than a 50% reduced weld cycle time, resulting in vastly increased welding productivity. The efficiency of the ClearDuct product doubles the volume of welds that can be achieved in the same time it takes to complete using conventional welding parameters.

ClearDuct ECD pipe

Peak Pipe Systems worked on the project in partnership with Eco-Drill. Dino Cancellara, Director of GD Hire and subcontractor for Eco-Drill commented “I used the ClearDuct pipe on the Hornsea wind farm project, it was the first time I had used this product and was very impressed with the presentation and design of the product. It was easy to install and lining up the markings to ensure consistent welding quality was very straightforward. This product doubled our finished pipe output in a day and the design meant no debeading is required which also meant production efficiency was improved massively. I would recommend this product for future installs.”

If you’re working on a large project that features a large amount of electrical cable and are looking for ECD solutions, please get in touch: +44 (0) 1246 262 702 | sales@peakpipesystems.com

ClearDuct brochure
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Bridgstock Group donate £40,000 to local Derbyshire and Yorkshire charities

After a tough year for businesses and individuals, we reflect on the positives of 2020 with generous hearts. Following the announcement of the global pandemic, the impact on businesses worldwide has been unprecedented.

If we take some time to think about not-for-profit charities, the strain on these worthy causes has never been more evident. For non-government funded charities less than a third of their total costs are covered by local health budgets, which means they are only able to provide excellent care to patients and their families because of the generosity of the community.

Eric Bridgstock, a pioneer in polyethylene pipe jointing who sadly passed away in 2018 always found ways to give back to the community and annually held charity events to raise well-needed donations to local charities.

His wife Petra, and her daughters Gemma, Helen and Ginnie (pictured) maintain a keen interest and involvement in the Bridgstock Group and are pleased to be able to make this donation to a local cause that is dear to their hearts.  

With this said and following a positive trading year the Bridgstock family have provided a generous donation of £40,000 to local charities.

Ashgate Hospicecare
Barbara-Anne Walker, Chief executive at Ashgate Hospicecare, said: “On behalf of everyone here at Ashgate Hospicecare, I would like to thank the Bridgstock Group for their kind generosity, which is gratefully received as we face our most difficult winter yet. 

Bluebell Wood Childre’s Hospice
Matthew Sheridan, Regional Fundraiser for Bluebell Wood, said: “We’d like to say a huge thank you to the Bridgstock Group for their overwhelming generosity which will help us make magical memories with local children and families. “It’s been a challenging year in which much of our fundraising activity has been cancelled or postponed, so the kindness of phenomenal supporters like the Bridgstock Group is more important than ever.”

St Luke’s Sheffield’s Hospice
St Luke’s Director of Income, Media and Marketing Kathryn Burkitt said: “Petra and her family have been keen supporters of St Luke’s for many years.

“This very special donation comes at the end of a very difficult year and will make an enormous difference to the lives of our patients and their families.”


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Do you know your SDR?

What is SDR and why is it important?

Pipe SDR is the abbreviated term for standard dimensional ratio. This simply refers to the mathematical relationship between the pipe outside diameter and its wall thickness. The SDR will refer to a wall thickness dimension which has been calculated to reflect the maximum operating pressure of the pipeline.

SDR is critically important when:

  • calculating the internal pressure of a pipe system.
  • the ID of the pipe is critical for example pumping mains to calculate pressure drops or volumetric data, or when inserting an item into the pipeline, such as an electric cable.
  • calculating the pipe tensile strength when putting under considerable installation stress, for example, HDD drilling.
  • Calculating the compressive strength of the pipeline to determine the depth of burial or compaction of backfill material.

How do I check the SDR or wall thickness of a pipe?

  • Simple mathematical equation. Pipe OD / the wall thickness of the pipe = SDR
  • Simple mathematical equation. Pipe OD / SDR11 = wall thickness
  • Physical measurement (if you have access to an open-end) with a bullnose micrometer.
  • Product markings

Example:

250mm (OD pipe) / SDR 11 = 22.72mm (wall thickness)
250mm (OD pipe) / 22.72 (wall thickness) = SDR 11

What if it’s already installed in the ground?

If the pipeline is already installed or you are trying to identify the SDR/wall thickness of an existing pipe in the ground, there are a few ways to do this.

  1. All pipes manufactured to industry-recognized water, gas and power standard are marked with 1 or 2 print lines which should remain fully visible and recognizable once installed. The markings will identify the SDR of the pipe and some even detail the wall thickness of the pipe too.

Example of pipe markings.

BS EN 12201 PEAK PIPE SYSTEMS (PPS1) BUREAU VERITAS 1144/001 225 X 20.5 MM SDR11 PE100 PN 16 B1 BATCH NO. DATE/TIME POLYMER CODE E.G. (B9L) W/P; MO. No.

  • You can either use an ultrasonic measuring device which measures the wall thickness of the pipe accurately, you can then determine the SDR of the pipe by using the calculation above.

What industry SDR are standard and readily available?

Over time the development of polyethylene materials and standard pipe SDR has changed and been developed in accordance with the MOP (max operating pressures) required for the pipe networks. Ensuring the suitability and longevity of the networks throughout the systems life cycle.

Below is a list of standard industry available SDR and how commonly they are stocked within the UK market.

Pipe SDR ratingAvailble as standardAvailable
to order
7.4Yes
9Yes
11Yes
13.6Yes
17Yes
17.6Yes
21Yes
26Yes
33Yes
41Yes

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Polyethylene Advantages in Aquaculture – Gael Force & Peak Pipe Systems

BACKGROUND

Our extensive design and manufacturing capabilities mean we can adapt to new challenges and help solve problems. While our strength lies in polyethylene products used in utilities and infrastructure, we often take on new and exciting projects that utilise polyethylene in an innovative way.

When Gael Force, a 260-strong aquaculture business, approached us to manufacture key components for their fish pen product, we quickly built a relationship based on trust and success.

Gael Force Marine began as a 1 man fishing creel manufacturer in the Outer Hebrides. After successful growth and a move to Inverness, the company retains its strong highland heritage and values. Gael Force has a long, established history in the aquaculture industry, and over the last few years its open-net pen fish farming products have become a key focus.

CHALLENGE

The aquaculture product in question is a floating fish pen named the SeaQurePen 500, which is built to operate in extremely harsh sea conditions. It must be able to float in high currents and survive tidal events that occur far away from the Scottish coast. The product offers heavy duty, robust design and in models of 120 to 200m circumference, built with PE material which is low in maintenance but offers lasting durability. It was developed with 30 years of industry experience both at home in Scotland and in global markets.

The SeaQurePen 500 is made up of a pair of concentric flotation pipes, which are joined with brackets. It features a deck system that has a plastic handrail for operator safety. Finally, there is a plastic sinker tube with a heavy steel chain or cable inside that weighs the net down. The pen provides easy access for operations, providing integrated hazard-free distribution of services around the pen.

In working with Peak Pipe Systems, Gael Force choose us because of our expertise. “It’s one thing to design a product. It’s another to design it and understand exactly how it’s going to be made. Peak bring the manufacturing knowledge right down to the heart of our design.”

RESULTS

Our work with Gael Force has set the standard in product quality. They have been continually impressed with our attention to detail, with Product Development Manager, Adam Young, commenting: “Peak are their own worst critics and will spot something they’re not happy with and resolve it themselves.”

Most importantly, our expert approach means we can offer Gael Force added value by delivering cost-efficiency. “The brackets designed are fantastic. Design allows us to create a more cost-effective product. Peak are very pro-active on the tooling and project management side, which has taken a lot of difficulty away from the project. Peak have managed the whole tool design process for us.”

Gael Force and Peak Pipe Systems have built an ongoing relationship built on mutual honesty and trust. We maintain a two-way dialogue so that Gael Force’s fish pen products are the best they can be – and we remain committed to being a trusted partner who can proactively offer solutions to any challenges.

Gael Force are leaders in the aquaculture industry and Peak Pipe Systems are exceptionally proud to work on their innovative products.

If you’d like to leverage our polyethylene manufacturing capabilities and expertise, approach us with your design challenge and see how we can add value.

Contact us today to discuss your project.

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To GIS, or not to GIS?

Peak Pipe Systems have obtained formal approval for a comprehensive range of butt-welded fabricated fittings suitable for use on low pressure (LP) and medium pressure (MP) gas networks up to 5.5 bar.

The approval is against the Gas Industry Standard (GIS) GIS/PL2-6:2018.  As part of the standard, there is a requirement for third-party verification, in the case of Peak Pipe Systems, this has been completed by BSI under the structure of their Kitemark™ Scheme.

The UK gas industry has spent decades developing the GIS range of documents, indeed they set a benchmark for the global gas industry as they are still referenced extensively around the world.

The Gas Distribution Networks (GDNs) in the UK, including the increasingly influential Independent Gas Transporters (IGTs), on the whole, continue to specify the GIS range of documents as a pre-requisite for product approval for installation or adoption into their respective networks.

But how confident can GDNs & IGTs be that the products in their networks meet the GIS requirements?

Peak Pipe Systems continually listen to their customers – end-users, distributors and other industry experts.  Peak’s largest distributor has a dedicated Technical Team who are responsible for ensuring that all gas products distributed by them are fully compliant to GIS – this is a key part of what makes them the UK’s leading supply chain partner for utilities and utility infrastructure providers.

This distributor’s Technical Team is constantly checking that products do not just have a certificate to show GIS compliance but, with the team’s extensive product and technical knowledge, that they truly meet the required standard.  Believe it or not – sometimes this is not the case.

The same Technical Team flagged an issue of this nature to all UK gas product suppliers – it related to PE stub flange kits for electrofusion jointing, used extensively for valve and other connections.  The stub flange lengths of all apparently GIS ‘approved’ suppliers did not meet the minimum length as defined in GIS/PL2-6:2018, Table 4.  This might have just been a technicality to some, but the distributor’s Technical Team realised this was more important as it meant that the installer could not actually clamp the electrofusion coupling properly and would therefore be forced to ‘improvise’ and build unnecessary risk into the network.

As a key manufacturing partner of their largest distributor, it was Peak Pipe Systems that reacted to the problem, they developed an extended stub flange product range and went through full GIS approval with the support of BSI.  The final sign off was with the distributor’s Technical Team.

Peak Pipe Systems are now offering the UK gas industry a fully compliant range of stub flanges and a wider range of butt-welded fabricated fittings suitable for use on low pressure (LP) and medium pressure (MP) gas networks up to 5.5 bar.

So, back to the question …… “To GIS, or not to GIS?”. 

Yes – but only if you buy your products from one of Peak Pipe System’s distributors.

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