Delivering Fluid Sealing Solutions Since 1972

Diaphragm Seals

Diaphragm Seals – Rolling and Flat

M Barnwell Services stands as one of the premier stockists, distributors, and manufacturers in the UK, offering an extensive range of Diaphragm Seals (both Rolling and Flat) and Hygienic Seals.

Our Diaphragm Seals are certified compliant with FDA, EC1935/2004 & EC2023/2006 European Regulations, KTW, USP Class VI, UL157, NSF 51, 3A (Sanitary), ACS, and DVGW standards.

These seals are crafted from a variety of materials including Perfluoroelastomer (FFKM), Nitrile (NBR), Hydrogenated Nitrile (HNBR), Viton® (FKM/FPM), Ethylene Propylene (EPDM), Silicone (VMQ), Neoprene (CR), and Fluorosilicone (FVMQ).

Rest assured, comprehensive documentation and certificates accompany our offerings.

Our capabilities extend to creating diaphragm seals tailored to match the unique shape and configuration demands of your application. We ensure the supply of the precise molding you need, with various finishes, cross-sectional thicknesses, and tolerances.

Our proficient team manages the entire production process, from prototyping and testing to final part manufacturing. Additionally, we offer specialised certification upon request.

If you would like more information about our range, download our catalogue, or contact a team member.

  Rolling Diaphragm SealsDiaphragm Seals

Diaphragm Overview

Diaphragm seals, often referred to as remote seals or chemical seals, serve two primary functions.

Firstly, they effectively isolate the measuring instrument from the process medium.

Secondly, they facilitate the accurate transmission of pressure to the measuring device. Notably, these seals are designed to be swiftly disassembled, allowing for convenient and efficient cleaning and calibration procedures when needed. This capability ensures optimal performance and reliability in various applications.

Diaphragm seals employ a flexible diaphragm to isolate the process side. System-fill fluid occupies the space between this diaphragm and the pressure measurement device. The diaphragm transmits pressure from the medium to the fluid, which then conveys it to the measuring component, such as the pressure-measuring instrument or transmitter.

In certain scenarios, a capillary may link the diaphragm seal to the pressure-measuring instrument. This connection serves to minimise temperature influences from hot fluids on the measuring instrument.

These seals are affixed to existing fittings or flanges, often utilising T-pieces integrated into pipelines or welding sockets attached to pipelines, process reactors, or tanks. This configuration yields a substantial “contact surface” between the diaphragm and the pressure medium, ensuring precise pressure measurement, particularly for low pressures (< 600 mbar).

Elastomeric diaphragm seals offer versatile dynamic sealing solutions, surpassing limitations of other seal types. They exhibit minimal friction, prevent leakage, and can accommodate low pressures. With careful material selection, diaphragms achieve effective sealing across wide temperature and pressure ranges, eliminating the need for lubrication or upkeep.

Benefiting from advanced design and materials, M Barnwell Services provides both standard and customised diaphragm seals and membranes, ensuring dependable performance across diverse applications.

Applications By Industry:

  • Automotive
    – Application: Monitoring pressure in automotive manufacturing processes.
    – Example: Measuring pressure in hydraulic systems used in automotive assembly lines.
  • Aerospace and Defence
    – Application: Pressure monitoring in aircraft systems and components.
    – Example: Measuring pressure in aircraft hydraulic systems.
  • Biotechnology
    – Application: Pressure measurement in bioreactors and fermentation processes.
    – Example: Monitoring pressure in a biotechnology research lab’s cell culture system.
  • Oil and Gas
    – Application: Pressure measurement in oil pipelines, refineries, and offshore platforms.
    – Example: Monitoring pressure in an oil drilling rig’s wellhead equipment.
  • Chemical Processing
    – Application: Monitoring pressure in corrosive chemical processes.
    – Example: Measuring pressure in a chemical reactor where aggressive chemicals are involved.
  • Food and Beverage
    – Application: Pressure monitoring in food processing and beverage production.
    – Example: Measuring pressure in a carbonation system for soft drink production.
  • Pharmaceutical 
    –  Application: Pressure measurement in pharmaceutical manufacturing processes.
    – Example: Monitoring pressure in a bioreactor during the production of pharmaceutical products.
  • Water Treatment
    – Application: Pressure measurement in water treatment plants.
    – Example: Monitoring pressure in a water filtration system to ensure efficient operation.
  • Petrochemical
    – Application: Pressure measurement in various stages of petrochemical production.
    – Example: Measuring pressure in a petrochemical distillation column.

These examples highlight the versatile use of diaphragm seals across industries, ensuring accurate pressure measurement while protecting sensitive measuring devices from harsh or potentially damaging process media.

You Are In Safe Hands

As a reliable partner to global OEM manufacturers, M Barnwell Services ensures quality products and an exceptional service experience. With £5.1 million in sealing inventory and five UK branches strategically positioned, we’re primed to meet and surpass your needs.

When delivering the optimal diaphragm for an application, our engineers take into account various factors: pressures, temperatures, expected mechanical loads, chemical substances, and the desired lifespan of the sealing component.

We offer Garlock’s specialised ONE-UP® Pump Diaphragms and GYLON® Style 3522 PTFE Diaphragms also.

For additional details about our product range, access our catalogue, explore the Seal Maker page, or contact a member of the team.

E & OE.


Many sizes as standard. Bespoke seals to suit your application


Perfluoroelastomer (FFKM), Nitrile (NBR), Hydrogenated Nitrile (HNBR), Viton® (FKM/FPM), Ethylene Propylene (EPDM), Silicone (VMQ), Neoprene (CR) Fluorosilicone (FVMQ), CIIR, ECO, and CSM 


 FDA, EC1935/2004 & EC2023/2006, KTW, USP Class VI, UL157, NSF 51, 3A (Sanitary), ACS, and DVGW grades