Comparing HEPWORTH with Other Plastic Systems
Comparing HEPWORTH with Other Plastic Systems
When a customer comes to our online shop asking "why should I buy HEPWORTH and not PP-R or PEX, which I know from another supplier", the answer is never a simple "because it's better". Every plastic pipework system has its place, its limits, and its price bracket. In this article we take a sober, marketing-free look at how HEPWORTH stacks up against the four most commonly used alternatives on the Slovak market - polypropylene PP-R, cross-linked polyethylene PEX, chlorinated PVC (PVC-C), and multilayer aluminium-plastic Al-PEX pipe. The goal isn't to convince you HEPWORTH is universally the best choice, but to put concrete figures and practical experience in your hands so you can choose for yourself based on what you're actually dealing with - a flat renovation, underfloor heating in a new build, or pipework to two radiators in a garage.
Why compare plastic systems at all
Just twenty years ago, the choice was simple - copper or steel. Today, plastic and multilayer systems, according to industry supplier estimates, already make up the majority of new heating pipework in both apartment buildings and family homes in Slovakia, because they're faster to install, easier to handle, and don't corrode. The problem is that "plastic pipe" isn't one category - it's a group of materials with significantly different properties that can't simply be swapped for each other. An installation company that normally works with PP-R won't have the necessary fittings on hand, nor experience welding a HEPWORTH system, and vice versa. That's why it's worth deciding in advance, before buying the first metre of pipe, since switching systems midway through a build costs you both time and money.
In practice, customers most often ask us three things: what pressure and temperature the material can handle, how demanding the joining process is, and whether the system can be combined with what they already have installed at home. We'll go through all three questions in turn.
Basic overview of the five systems
Before we get into the details, let's look at a table overview of the key parameters. The values are based on commonly declared manufacturer data sheets for pipes intended for hot-water heating and domestic hot water distribution, not extreme laboratory conditions.
The table reveals an important first fact - HEPWORTH isn't the toughest system in terms of pressure. Its PN10 is more than enough for most typical hot-water heating circuits in family homes and flats, where operating pressure is typically between 1.5 and 3 bar, but for larger apartment buildings with taller risers or for industrial applications requiring PN16 or PN20, PP-R is the more suitable choice.
Temperature and pressure resistance in practice
The theoretical figures from the data sheet are one thing, real-world conditions are another. In practice it's important to distinguish between continuous operating temperature (the temperature the material can withstand for decades without degrading) and short-term peak temperature (for example if the boiler's control malfunctions and the water temperature briefly spikes above the normal range).
HEPWORTH is designed for a continuous operating temperature of 70 °C, which covers practically all typical heating systems with condensing boilers, where the heating water's outlet temperature is typically between 45 and 65 °C. Short-term it can handle peaks up to 95 °C, an important safety margin in case of a fault or temporary boiler overheating. PP-R formally has the same temperature parameters, but thanks to its higher pressure rating (PN20) it has a bigger margin even when high temperature and high pressure occur together - which is why PP-R is more commonly seen in industrial boiler rooms and larger apartment buildings.
PEX behaves the opposite way - it's more flexible and better tolerates mechanical stress (for example water freezing in the pipe, which shape-memory plastic tubing can "survive" without cracking better than rigid pipes), but its pressure resistance is lower, typically PN6 to PN10 depending on wall thickness and manufacturer. That's why PEX is used almost exclusively in underfloor heating, where pressure is low and the main requirement is precisely flexibility when laying it in loops without unnecessary joints.
PVC-C, less common here, is interesting in that it can withstand temperatures up to 95 °C even continuously, but it's more brittle at low temperatures and cracks more easily than PP-R or HEPWORTH under mechanical impact (for example careless handling during winter installation). It therefore needs to be handled more carefully during storage and transport, especially in the winter months.
Al-PEX combines the advantages of both worlds - the aluminium layer between two layers of PEX prevents oxygen diffusion into the water (important in closed heating circuits, where diffused oxygen accelerates corrosion of steel radiators and boiler heat exchangers), while also giving the pipe shape memory - you bend it into the required shape and it holds it, which doesn't work with plain PEX.
Joining method - where HEPWORTH wins and where it loses
This is the area where the systems differ perhaps the most, and where the choice has the biggest impact on what installation company you'll need to find and how much the labour will cost you.
HEPWORTH, like PP-R, is joined by welding - either butt welding directly at the pipe ends (for larger diameters), or electrofusion via a fitting with an embedded resistance wire, which is powered by current and melts the plastic from inside both the fitting and the pipe simultaneously. The advantage is that a correctly made weld creates a homogeneous joint - the pipe and fitting material literally fuse into one piece, meaning zero risk of joint leaks when the work is done correctly. The downside is that this method requires a welding kit, electricity on site, and a trained installer - it's not a job a home DIYer can do over a weekend without experience.
PEX and Al-PEX, by contrast, are joined mechanically - with press fittings that slide onto the pipe end and are pressed with special pliers. This method is faster, requires no electricity or welding kit, and is easier to learn, but the joint is mechanical, not homogeneous - correct sizing and the quality of the press pliers therefore play a key role. With some joint types (for example compression fittings), the joint can also be taken apart and reassembled if needed, which isn't possible with welded HEPWORTH or PP-R joints - once welded, a joint is permanent.
It's precisely with mechanical joints that a good-quality fitting matters. Our range includes, for example, the Compression fitting for copper pipe 15x1-EK, which, while used primarily for copper pipework, embodies exactly the principle of a compression joint - a joint that can be taken apart at any time without having to cut the pipe - that you'll appreciate when designing pipework combining several materials (for example a transition from copper to plastic). More specific details are in the product table below.
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Compression fitting for copper pipe - 15x1-EK - a detachable joint for transition points between different pipework materials, for example where you're connecting a plastic system to an existing copper section. Useful for combined renovations, when you're not replacing the whole pipework at once. From €2.51. |
Price comparison per running metre
Price is the factor that interests customers the most, yet it's also the hardest to compare objectively, since it depends on diameter, pressure class, and the current situation on the plastics market (especially for PEX and Al-PEX, where price fluctuates with oil prices more noticeably than for other materials). Below is an approximate price index, where HEPWORTH represents a baseline value of 100.
The chart shows that both HEPWORTH and PP-R are among the most affordable options, PVC-C is somewhat more expensive, and the most expensive are the flexible PEX and especially the multilayer Al-PEX systems, where on top of the material price you also pay for pricier press fittings and specialised tools (press pliers, calibrators). It should be stressed, though, that this is only the material price - in the overall project budget, the installer's labour cost, the number of fittings needed, and the length of the job often matter more than just the price per metre of pipe.
Where HEPWORTH is the best fit
Based on experience with the installation companies that buy from us, HEPWORTH most often shows up in these situations:
- Hot water and heating pipework in family homes and flats, where operating pressure doesn't exceed the typical 3-4 bar.
- Renovations, where older steel or copper pipework is being replaced and the client wants a homogeneous, welded system without mechanical joints that might "sweat" or loosen over time.
- Smaller boiler rooms and utility spaces, where reliable pipework to several branches at once is needed - for example to a manifold.
It's precisely when running pipework to several branches that a good-quality manifold is worth using. Our range includes, for example, the 4-circuit manifold with valve, 15x15x15x15, which is exactly suited to the situation where you need to split water from one main HEPWORTH pipe run into four independently shut-off branches - for example to radiators in different rooms, or to a combination of radiators and underfloor heating.
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4-circuit with valve, 15 x 15 x 15 x 15 - a practical solution for splitting the main heating pipework into four independently regulated branches, ideal for combining several rooms or heating types on one system. From €41.69. |
Where a different alternative is more suitable
It's just as fair to say when HEPWORTH isn't the first choice:
- Underfloor heating - here we clearly recommend PEX or Al-PEX, since you need long, flexible loops with no joints, run inside the floor slab. HEPWORTH is welded in rigid sections, which isn't practical for underfloor heating.
- High-pressure industrial pipework beyond PN10 - here PP-R with its PN20 rating has a clear advantage.
- Frequent layout changes and modifications (for example in premises where the layout changes every few years) - mechanically joined PEX/Al-PEX systems are easier to modify without needing welding equipment on site.
Installation and pipe mounting - a detail that gets forgotten
Regardless of which material you choose, the quality of how the pipe is fixed to the building structure matters just as much for the system's lifespan as the pipe material itself. Plastic pipe moves significantly more with thermal expansion than metal - with both HEPWORTH and PP-R you need to allow for expansion that the mounting must accommodate, otherwise mechanical stress builds up at the joints.
For machine-assisted pipe mounting during installation, we recommend good-quality clips, for example the HS clips 45mm for machine-assisted pipe mounting, which are joined with wire into a strip and allow fast, repeatable mounting over larger sections of pipework - typically in utility rooms or where pipes run along a wall in a large number of parallel runs.
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HS clips 45mm for machine-assisted pipe mounting, joined with wire into a strip - fast and reliable mounting of plastic pipe to the building structure, suitable for HEPWORTH and other plastic systems alike where there are many parallel runs. From €21.77. |
Terminating the run - the radiator connection
Whichever pipework system you choose, you'll need a good-quality radiator valve at the end to allow precise room temperature control. We recommend, for example, the Thermostatic radiator valve - straight, EK x 1/2", which can be connected to plastic pipework via a suitable transition fitting and provides precise thermostatic control regardless of whether the supply pipe is HEPWORTH, PP-R or PEX.
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Thermostatic radiator valve - straight, EK x 1/2" - precise thermostatic control at the end of a heating circuit, compatible with connections from both plastic and metal pipework via a suitable transition fitting. From €8.58. |
Combining systems - yes or no?
A common question from customers who have a partially existing pipework system at home is: "can I connect HEPWORTH to an old PP-R or copper run?" The answer is yes, but with a condition - directly welding HEPWORTH to PP-R pipe isn't recommended, since these are different materials with different melting temperatures and chemical compositions, even though they look similar. A reliable solution is a mechanical transition via a transition fitting or a compression fitting, which creates a safe, sealed joint without having to "rely on" the compatibility of two different plastics. Transitioning to copper pipe is simpler, since standard metal-to-plastic transition fittings with a certified seal are already commonly used there.
An important warning - never combine purely copper and purely aluminium (Al-PEX) components in the same closed circuit without electrical isolation, since contact between two different metals in the presence of water causes galvanic corrosion. This doesn't apply to HEPWORTH or PP-R, since they're purely plastic materials with no metal component - one of their advantages over Al-PEX precisely in terms of the circuit's long-term chemical stability.
Filtration and system protection regardless of material
Whichever of the five systems above you choose, the lifespan of the whole heating circuit is significantly extended by good-quality inlet water filtration, which prevents mechanical debris and limescale from settling in the boiler, the pump, and the pipework itself. We recommend, for example, the Cyclonic sediment filter 4" - 1/2"F, which is fitted at the system inlet and mechanically removes debris using a centrifugal principle, with no need to replace a cartridge during normal operation.
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Cyclonic sediment filter 4" - 1/2"F - protects the whole heating system, regardless of whether the pipework is HEPWORTH, PP-R or another plastic system, from mechanical debris entering the circuit. From €102.34. |
Summary - a quick decision overview
If we had to sum up the whole comparison in one sentence per system, it would look like this: HEPWORTH is a reliable, affordable choice for typical home heating and DHW pipework with welded, permanent joints. PP-R is its almost identical sibling with a higher pressure rating, suitable where HEPWORTH isn't enough pressure-wise. PEX is the king of underfloor heating thanks to its flexibility, but at a higher price. PVC-C is a minority choice with good temperature resistance but more mechanically brittle. Al-PEX is the most versatile, but also the most expensive, ideal where you need a combination of flexibility, shape memory, and oxygen-diffusion resistance.
As you can see, with the exception of PVC-C, the declared lifespan barely differs between systems - so the difference isn't "which material lasts longer", but which system better suits a specific application, what pressure and temperature margins it has, and what installation technique it requires. That's exactly why there's no clear winner - there's only a right or wrong choice for the given situation.
Practical experience from installations
The installation companies we regularly talk to confirm one recurring pattern - most problems in the field don't come from choosing the wrong material, but from combining it incorrectly with unsuitable accessories. A typical example is using a cheap, poor-quality fitting on a press-fitted PEX joint, which after a few years of thermal cycling starts to "weep" slightly - the joint hasn't fully opened up, but moisture appears right at the joint. With welded systems like HEPWORTH or PP-R, this problem practically doesn't occur, since a correctly made weld is homogeneous and has no "weak point" in the form of a mechanical seal. This is a decisive argument in favour of welded systems anywhere access to that pipe section is limited or impossible without demolition work once it's built into a wall or floor.
On the other hand, for repeated layout changes (for example in commercial premises where partition layouts, and with them the pipework route, change every few years), installation companies clearly prefer mechanically joined systems, since modifying the route doesn't require welding equipment on site and is faster and cheaper in terms of labour.
Frequently asked questions
Can HEPWORTH pipe be directly welded to PP-R pipe?
We don't recommend it. Even though both materials look visually similar and have close technical parameters, they're different plastic formulations that behave differently when melted. A safer solution is a mechanical transition - for example a suitable transition fitting or a compression fitting - which creates a reliable joint without relying on the compatibility of two different materials.
Is HEPWORTH suitable for underfloor heating?
It isn't the first choice. Underfloor heating needs long, flexible loops laid inside the floor slab with no unnecessary joints, which PEX or Al-PEX handles better thanks to its flexibility. HEPWORTH is better suited to rigid pipework to radiators and manifolds, not to the loops themselves in the floor.
Why does HEPWORTH have a lower pressure rating than PP-R?
It comes down to different polymer formulations and wall thicknesses at a comparable pipe diameter. PP-R with a PN20 rating is designed with a larger pressure margin for industrial and larger apartment-building applications, while HEPWORTH at PN10 is optimised for typical home pipework, where such a margin isn't needed, making the material somewhat cheaper.
Is it worth investing in more expensive Al-PEX instead of cheaper HEPWORTH?
It depends on the application. If you're dealing with simple pipework to radiators in a family home at typical pressure and temperature, HEPWORTH provides the same declared 50-year lifespan at a lower price. Al-PEX is worth it where you need a combination of flexibility, shape memory, and oxygen-diffusion resistance, for example on more complex routes through tight spaces.
How does a welded HEPWORTH joint last compared with a pressed PEX joint?
With correct installation of both systems, manufacturers declare the same 50-year lifespan. The difference isn't in the declared lifespan, but in the fact that a welded joint is homogeneous and has no mechanical seal that could theoretically degrade over time, while the quality of a pressed joint depends on correctly using certified tools and fittings.
Can I install HEPWORTH myself without a welding kit?
That's not common practice. Both butt welding and electrofusion welding require a specialised welding kit and training to ensure the joint is genuinely homogeneous and sealed. For a DIY home installation with no prior experience, mechanically joined systems like PEX or Al-PEX with press or compression fittings are more suitable.
Related topics
What is the HEPWORTH system and what is it used for
How to choose the right HEPWORTH components
Installing the HEPWORTH pipe system
Joining and sealing HEPWORTH pipework
HEPWORTH Heating - Professional and Simple
Have a question on this topic?
Can't decide, or dealing with a specific situation in your home? Write to us - we're happy to help.