Pinch Valves
The Atval technology is developed in South Africa in conjunction with the local mining industry, which requires valves to handle slurries at higher pressures than anywhere else in the world. The pinch valve is an ideal product for this application because of its full-unrestricted flow pattern and the use of gum rubber as an abrasion resistant closing membrane.
The product range is from 25mm to 1000mm with working pressure in the range of 10bar to 60bar (Class 150 – Class 900).
The temperature range is -20° to +120° centigrade.
Atval offer a comprehensive range of valves which is purposely designed for:
- Low – and high pressure applications
- Fluid and powder metering and flow control
- Abrasive transport systems
Atval Pinch Valves Product Range
Pinch Valves for South African Industry & Mining
Pinch valves are the workhorse isolation and control valve for any application where the medium is abrasive, slurry-based, or where solids would jam a conventional valve seat. DFC supplies the full Atval Pinch Valve Range in South Africa — including the K and KE Series with 25 years of proven local service, and the Utility Control Series with 50 years of proven service — to mining houses, water boards, mineral-processing plants, sewage treatment works, pulp and paper mills, and chemical producers.
The defining advantage of a Pinch Valve is that the only wetted component is the elastomer sleeve. The valve has no seats, no stems passing through the flow path, and no cavities for solids to settle in. The sleeve itself is a serviceable consumable that can be replaced in the field, which is why Pinch Valves dominate slurry duty in South African mining.
The Atval Range covers five distinct Pinch Valve series — Truflo, K, KE, C-Series and Utility Control — alongside the corresponding replacement sleeves. Atval also manufactures sleeves to fit competitor Pinch Valves; if you have a non-Atval Pinch Valve in service, contact our engineering team with the original sleeve dimensions and we will quote on a custom-moulded equivalent.
What is a Pinch Valve?
A Pinch Valve is a linear-motion valve in which a flexible elastomer sleeve is the only wetted component. Closure is achieved by mechanically pinching the sleeve closed — either via opposing bars (mechanical) or by injecting compressed air or fluid into the valve body cavity around the sleeve (air-actuated).
Because the medium only ever contacts the sleeve, Pinch Valves have several decisive advantages over conventional gate, butterfly, and ball valves in abrasive or solids-bearing duty:
- Full-bore, full-flow design — the valve presents the same internal diameter as the pipeline when fully open, with no turbulence and no head loss.
- Self-cleaning flexing action of the sleeve eliminates inline scaling and line blockage.
- Drop-tight, bi-directional shut-off across the entire pressure rating.
- All mechanical parts are completely isolated from the pipeline medium.
- Field-replaceable sleeves extend in-line service and lower maintenance costs.
- All Atval Pinch Valves accept all forms of actuators — manual, pneumatic, electric and hydraulic. All sleeves are independently tested prior to dispatch and supplied with test certificates.
These characteristics are why Pinch Valves dominate slurry isolation in mining, sewage and sludge handling at water treatment works, and powder/granule isolation at process plants.
Where Pinch Valves Outperform
Atval Pinch Valves are deployed across mining, mineral processing, power generation, sewage treatment, pulp and paper, chemical processing, and food production. They handle abrasive slurry, raw sewage, sludge, slime, grease, grit, lime mud, hydrocarbons, and aggressive chemistry — applications where conventional valves wear out fast or fail to seal at all.
The table below maps the most common DFC Pinch Valve applications to a suggested Atval series and sleeve grade. This is general guidance — final selection should be confirmed with our engineering team against the actual operating conditions.
| Industry | Typical Duty | Suggested Series | Suggested Sleeve Grade |
|---|---|---|---|
| Mining (slurry) | Mill discharge, cyclone feed, tailings | K / KE Series | B (natural rubber, abrasion + ozone) or A (gun rubber + soft red lining) |
| Mineral processing | Concentrate transfer, dewatering | K / KE Series | B or A |
| Power generation | Slurry, lime, ash duty | C-Series or K / KE | B or E (EPDM, chemical resistance) |
| Sewage treatment | Raw sewage, sludge, slime, grease, grit | C-Series | B or E |
| Pulp and paper | Stock slurry, lime mud, additives | C-Series or K / KE | B or E |
| Chemical processing | Aggressive chemistry, polymer transfer | K / KE Series | E (EPDM), F (Butyl, acid resistance), or D (Nitrile, hydrocarbons) |
| Food processing | Hygienic-duty product isolation | Utility Control or C-Series | C (food-grade natural rubber, Food Processing Industry approval) |
| Flow control / dosing | Modulating, throttling, repeatable linear flow | Utility Control (purpose-designed for control) | Match medium to grade |
For specific selection against your duty conditions — pressure, temperature, particle size, chemistry, cycle frequency — contact our engineering team.
Atval Pinch Valve Range — at-a-Glance Comparison
The five Atval Pinch Valve series cover the full range of South African industrial duty, from low-pressure dosing to high-pressure mining slurry. Where higher pressures or larger sizes are required than those listed below, contact our engineering team.
| Series | Size Range | Working Pressure | Designed For |
|---|---|---|---|
| Truflo (single anvil) | 25 – 300 mm | Normal CWP 1000 kPa (10 bar); higher on request | Direct replacement for diaphragm valves; same face-to-face dimension; straight-line flow with no cavities |
| K Series | Consult DFC for size by CWP rating | Max 1600 kPa (16 bar) | Abrasive and slurry duty; mining; 25 years proven service; full bore, full flow; reduces water hammer |
| KE Series | 25 – 500 mm | Max 4000 kPa (40 bar) | High-pressure abrasive and slurry duty; mining and process; CWP ratings 2500 / 4000 kPa from local manufacturing |
| C-Series | 25 – 1000 mm | Pressure drop should not exceed 25% | Sewage, pulp and paper, mining, chemical, power generation; cast iron or aluminium body |
| Utility Control | 25 – 300 mm | Consult our team for the application | Throttling and accurate repeatable linear flow control; 50 years proven service; ~90% flow at full open |
Notes: K and KE Series are sister products with shared design and tooling — the K Series tops out at 1600 kPa, and the KE Series goes up to 4000 kPa. The K and KE Family is offered with CWP ratings of 1000, 1600, 2500 and 4000 kPa from local manufacturing.
Pinch Valve vs. Knife Gate, Butterfly and Diaphragm Valves
Choosing between a Pinch Valve and an alternative valve type usually comes down to the medium, the cycle frequency, and the maintenance philosophy. The notes below are general engineering guidance; for borderline applications, our engineering team can model expected sleeve life against the alternative valve’s seat life.
Pinch Valve vs. Knife Gate Valve
Knife Gate Valves are familiar to mining personnel and lower-cost up front, but they typically suffer rapidly under abrasive duty: the knife edge wears, the seat erodes, and stem packings can develop leaks. A Pinch Valve has no stem in the flow path and no metal-to-metal sealing surfaces, so cycle life in abrasive slurry duty is generally longer. For mill discharge, cyclone feed, and tailings — Pinch Valves are typically preferred.
Pinch Valve vs. Butterfly Valve
Butterfly Valves are excellent for clean fluids and on/off duty in water and air, but they have a disc permanently in the flow stream. In slurry or solids duty the disc and seat wear, and the valve can develop leaks. Pinch valves provide unobstructed full-bore flow when fully open and a positive seal regardless of the medium. Butterfly for clean — pinch for dirty.
Pinch Valve vs. Diaphragm Valve
The single-anvil Truflo Pinch Valve is designed as a direct replacement for diaphragm valves. It is supplied with the same face-to-face dimension as a diaphragm valve, allowing direct swap-out in existing pipelines. Truflo offers full unrestricted flow (versus the partial restriction of a diaphragm valve’s weir or saddle) and a self-cleaning flexing action. For applications where solids or slurry would shorten diaphragm life, a Truflo Pinch Valve is the direct upgrade.
Pinch Valve Sleeves — Material Grading
The sleeve is the heart of the Pinch Valve. It is the only wetted component, and it is the only part that typically wears in service. Atval Sleeves are graded by material — the table below covers the seven sleeve grades available, with the verified service temperature range for each.
| Grade | Colour | Material & Application | Temp Range |
|---|---|---|---|
| A | Black with welted parts red | Gun rubber faced sleeve with a 6 mm internal lining of soft red rubber. On abrasive services, this lining can outlast the ‘B’ Grade sleeve. | −30°C to +70°C |
| B | Black | Natural rubber specially formulated for abrasion and ozone resistance. | −30°C to +80°C |
| C | Red | Specially formulated natural rubber, free of carbon black. Carries approval by the Food Processing Industry. | −30°C to +70°C |
| D | Black | General-purpose nitrile rubber (also known as BUNA-N). Resistant to oils, hydrocarbons and some chemicals. | −20°C to +120°C |
| E | Black | Ethylene Propylene Polymer (EPDM) with good abrasion resistance. Resistant to most chemicals. | −30°C to +120°C |
| F | Black | General-purpose Butyl rubber with good acid resistance. | −30°C to +120°C |
| T | Black | General-purpose Neoprene, resistant to oil and moderate chemicals and acids. | −30°C to +90°C |
Replacement Sleeves for non-Atval Pinch Valves
Atval has, over the years, manufactured Pinch Valve sleeves to fit all the leading brands available on the world market. If you have a Pinch Valve that needs a replacement sleeve, contact us with the original sleeve dimensions or part number — there is a good chance the sleeve is in our portfolio, often at a lower price than the original equipment manufacturer’s part.
Pinch Valve FAQ
What is the difference between the K Series and KE Series Pinch Valves?
The K and KE Series are sister products in the Atval Range. The K Series has a maximum working pressure of 1600 kPa (16 bar), while the KE Series goes up to 4000 kPa (40 bar). The KE Series covers sizes 25 mm to 500 mm. The K and KE Family is offered with CWP ratings of 1000, 1600, 2500 and 4000 kPa from local manufacturing. Both series share the same core design — full bore, full flow, drop-tight bi-directional shut-off, and field-replaceable sleeves — and accept pneumatic, electric or hydraulic actuators.
When should I choose a Truflo Pinch Valve over the other Atval series?
The single-anvil Truflo is designed as a direct replacement for diaphragm valves. It has the same face-to-face dimension as a diaphragm valve, so it can swap into an existing diaphragm-valve installation without piping modifications. Truflo is supplied in sizes 25 mm to 300 mm with a normal CWP of 1000 kPa (10 bar); higher pressures are available on request. Choose Truflo when the application currently uses (or would otherwise specify) a diaphragm valve and you want full unrestricted flow plus self-cleaning sleeve action.
Can a Pinch Valve be used for flow control, or only on/off isolation?
Both. The Atval Utility Control Pinch Valve is purpose-designed for modulating duty: it is pre-pinched for accurate, repeatable linear flow control, with 50 years of proven service. The other Atval series (Truflo, K, KE, C-Series) are typically specified for on/off isolation. For continuous high-cycle modulating service, the Utility Control Series is the correct selection.
What sleeve material should I specify?
Atval Sleeves are available in seven grades: A (gun rubber + soft red lining for abrasive duty), B (natural rubber, abrasion + ozone), C (food-grade natural rubber, Food Processing Industry approved), D (nitrile / BUNA-N for oils and hydrocarbons), E (EPDM for general chemicals), F (butyl for acids), and T (neoprene for oils and moderate chemicals/acids). Temperature ranges vary by grade — see the sleeve grading table above. For specific selection against your duty conditions, contact our engineering team.
Do you supply replacement Pinch Valve sleeves for non-Atval Pinch Valves?
Yes. Atval has, over the years, manufactured Pinch Valve sleeves to fit all the leading brands available on the world market. Contact us with the original sleeve dimensions or part number — there is a good chance the sleeve is in our portfolio, often at a lower price than the original equipment manufacturer’s part.
Why Choose DFC for Pinch Valves in South Africa
DFC supplies the full Atval Pinch Valve Range in South Africa. The K and KE Series have 25 years of proven local service, and the Utility Control Series has 50 years of proven service. The K and KE Family is manufactured locally, with CWP ratings of 1000, 1600, 2500 and 4000 kPa available.
Our engineering team supports clients with valve selection, sleeve grade recommendation, and on-site application support. Sleeves are available across the full Atval valve range, and we can also supply sleeves for non-Atval Pinch Valves — contact us with the original sleeve dimensions for a quote.