Penstocks – UK-Made HDPE & Stainless Steel Penstock Valves
Penstocks (also known as sluice gates) are vital components in water flow control — designed to regulate, isolate or redirect flows in drainage, flood defence, infrastructure and industrial applications. With over 30 years’ experience behind us, AQUIKO delivers high-performance penstocks that combine precision engineering with real-world durability.
Why choose AQUIKO Penstocks
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UK-designed and manufactured for rapid supply and on-site support.
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Materials of choice: HDPE and stainless steel 316 — engineered for longevity (50-year design life).
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High specification ratings: standard wall-mounted models up to 6 m w.c. (metres water column) head pressure; lightweight options up to 3 m w.c.
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Comprehensive service: fixing kits included, full ancillaries available, custom sizes and spans catered for.
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Suitable for both resellers and contractors — stocked components, rapid dispatch, and expert technical back-up.
Our Range of Penstocks
Wall-Mounted Penstocks
Ideal for vertical installations where you need simple, robust isolation. AQUIKO’s standard wall-mounted penstocks are rated for up to 6 m w.c. head pressure and offer manual or actuated operation.
Inline Penstocks
Perfect for pipeline or culvert installations, inline penstocks are installed within the flow path. These units allow smooth integration into pressurised or free-flow systems and are available in HDPE or stainless steel.
Flush Invert Penstocks
Designed for installations where the bottom of the penstock must be flush with the invert of the pipe or channel. These models provide minimal disruption and allow maintenance access without flow interruption.
Weir Penstocks
Manufactured for weir and spillway applications, our weir penstocks combine heavy duty build with smooth operation to control water levels accurately.
Channel Penstocks
Tailored for open channel flow applications — with wide spans, deep sections and bespoke mounting arrangements to suit large civil projects.
Custom Penstocks
If your project demands non-standard size, pressure rating or material specification, our custom penstock service delivers. From drawing review to delivery, we work with you every step of the way.
Technical Specifications & Material Choices
Choosing the right material makes a significant difference. Our HDPE penstocks offer excellent corrosion resistance, low maintenance and are lightweight — ideal for many UK applications. When conditions demand the ultimate in durability and performance, our stainless steel 316 penstocks provide exceptional strength and service life, outperforming 304 in aggressive environments (see our detailed comparison datasheet).
Head pressure ratings:
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Standard: up to 6 m w.c. for wall-mounted models
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Flood Defence: minimum 6 m w.c.
All units are supplied complete with fixing kits and a full range of ancillaries.
Support, Availability & Ancillaries
From same-day dispatch on stocked items to bespoke manufacturing runs, AQUIKO ensures you receive strong support throughout your project. Our penstock range is backed by:
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Full fixing kits supplied with each unit
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Ancillary components (hand wheels, spindle extensions, actuators) to complete the installation in one place
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Technical advice and detailed drawings available
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A trusted supply chain for resellers, with rapid nationwide delivery in the UK
Get in Touch – Let’s Discuss Your Project
Whether you’re a contractor looking for a stock-ready solution or a reseller seeking partner-level pricing, AQUIKO has the penstock solution for you. Reach out today to discuss your requirements, request a quote or order a datasheet.
Contact us or call 01777 819 734
What is a penstock?
In drainage and flood defence, a penstock is a gate that slides across an opening to stop, isolate or control the flow of water. It sits in a frame fixed to a wall, channel or pipe, and is opened and closed by turning a spindle with a hand wheel or key. Penstocks are used to isolate attenuation tanks, chambers and pipelines for maintenance, to hold water back during a flood, and to control water levels.
The word also has another meaning in hydropower, where a penstock is the large pipe that carries water to a turbine. Our penstocks are the drainage kind: water control gates for surface water, sewers, outfalls and channels.
Types of penstock
| Type | What it does | Typical use |
|---|---|---|
| Wall-mounted penstock | Bolts to a wall over a pipe or opening | Chambers, attenuation tanks and outfalls |
| Channel penstock | Fits between the walls of an open channel | Open channels and ditches |
| Flush invert penstock | Seals at floor level with no lip at the bottom | Where flow and silt must pass freely |
| Inline penstock | Fits in the pipeline | Isolating pipes without a chamber wall |
| Weir penstock | Water flows over the top of the gate | Setting and holding upstream water levels |
| Flood defence penstock | Seals against high back pressure | Outfalls through flood walls and embankments |
| Hand stop | Compact isolation gate operated by hand | Temporary isolation of small channels |
| Custom penstock | Made to suit | Sizes over 1500mm and special requirements |
HDPE penstocks
An HDPE penstock is made from high-density polyethylene instead of cast iron or steel. It weighs a fraction as much, so smaller sizes can often be fitted without lifting gear. It doesn’t rust or corrode in sewage, sea water or aggressive ground, and it has little scrap value, so it isn’t a target for metal theft.
AQUIKO HDPE penstocks are made in the UK in wall-mounted, channel, flush invert, inline and weir versions. Choose stainless steel 316 for aggressive environments or where extra strength is needed. Read more in Why HDPE for penstocks and flap valves.
See our HDPE penstocks.
Wall-mounted penstock sizes
Standard wall-mounted penstocks are made in the UK from 100mm to 1500mm. Choose a size for drawings, datasheets and a quote:
| 100mm | 150mm | 200mm | 250mm |
| 300mm | 400mm | 500mm | 600mm |
| 700mm | 800mm | 900mm | 1000mm |
| 1100mm | 1200mm | 1300mm | 1400mm |
| 1500mm | Over 1500mm: see custom penstocks | ||
How penstocks are operated
Most penstocks are opened and closed by turning a threaded spindle. We supply everything needed to operate them, from the chamber floor or from ground level:
- Hand wheels for direct operation at the penstock
- T-keys for operating from above, through a cover
- Extension spindles in 1m, 1.5m and 2m lengths to reach from ground level
- S-cranks for easier turning on larger gates
- Pedestals, floor-mounted or wall-mounted, to support the spindle at a comfortable height
See all penstock ancillaries.
Penstock or sluice gate?
The two words are often used for the same thing. In UK drainage, “penstock” usually means a standard gate in a frame, sized to a pipe or chamber opening, while “sluice gate” is more often used for larger gates on rivers, reservoirs and flood schemes. For standard sizes up to 1500mm, AQUIKO penstocks are the quick, cost-effective option. For large engineered sluice gates, our sister company Aquatic Control Engineering designs and installs bespoke gates.
Penstock FAQs
Is a penstock a valve?
It does the same job as a valve: it opens, closes or controls flow. But a penstock is a sliding gate in a frame, rather than a valve body in a pipeline, so it can be fitted over openings, channels and chamber walls.
What pressure can a penstock hold?
Our standard wall-mounted penstocks are rated up to 6m water column. Flood defence penstocks are rated to a minimum of 6m water column. Ask us if your site needs more.
HDPE or stainless steel?
HDPE penstocks are light, corrosion-free and low maintenance, and suit most UK drainage work. Stainless steel 316 penstocks are for the most demanding or aggressive environments.
Can you make a penstock larger than 1500mm?
Yes. Anything over 1500mm is made to order as a custom penstock.
How do I get a price?
Trade customers can log in to see prices. Otherwise request a quote or call 01777 819734 and we’ll come back the same working day.
How do I choose the right penstock size?
Match the penstock to the pipe bore or opening it closes, then check the head of water it must hold against the rating. Send us the bore, invert level and head and we’ll recommend a size and rating.
More answers in our flap valve and penstock FAQs.
