devlon v-api

We have seen other materials in the course of these in-depth reviews today we look at Devlon® V-API.

Devlon® V-API is a polyamide material, developed by James Walker with the valve industry and subsequently approved and endorsed by oil and gas manufacturers.
The formulation of this material was specifically designed to accompany improved performance over a wide range of temperatures and pressures.
Devlon® V-API can be used in different formats that can be round and tubular.


The features concerning Devlon® V-API are:

  • high impact resistance
  • no deterioration
  • high capacity to resist mould and absorb water
  • low friction
  • high capacity to withstand shocks and abrasions
  • operating temperature -50°C + 176°C
  • suitable for use with high temperatures or pressures
  • low moisture absorption

Devlon® consists of three main components, the raw material, plus an activator and catalyst required for polymerisation.
A series of additives such as plasticisers, lubricants and heat stabilisers can be used to modify and improve the qualities of the material.
What differentiates Devlon from the competition is the technology behind these additives.
By varying the volume of additive components, materials with specific properties are produced to meet the requirements of each customer application.


Devlon® V-API’s low moisture absorption characteristic, which guarantees high stability, combined with its other characteristics, make it an indispensable product for use in applications requiring weight savings, and wear resistance.
This is why its use is most in demand for valve seats and inserts, clamps, beam spacers, rollers, bearings.
It has also been approved for use by major oil and gas producers.
James Walker thus became the leading supplier of seals for fluid items in connection with the world’s oil and gas producers; Devlon valves are in fact used in oil and gas pipelines.
A major problem in this sector is explosive decompression.
Valves that use seals to hold gaseous fluids in place when it may occur that the gas goes from a high to a low pressure level occupy an important place in this scenario.


Devlon is a material that includes additives that enable it to operate at much higher pressures and temperatures compared to soft valve seat materials.
The advantages of Devlon® V-API valves are:

  • the single material replaces a range of thermoplastics
  • higher pressure and temperature than PTFE, or nylon 6
  • can be produced in diameters from 1/2″ to 77″.
  • available in billet form, or as semi-finished or fully machined valves
  • excellent machining allows the creation of the desired surface finish
  • approved in operation at a pressure of 414 bar ( 6000 psi ) at + 176°C ( 350°F ), dependent on valve and seat design
  • the low level of moisture absorption improves dimensional stability
  • dimensional stability superior to PTFE used at high pressure
  • excellent wear and abrasion resistance compliant for sealing pressure valve applications

The Devlon® V-API ensures products with the functionality to guarantee the highest reliability under difficult operating conditions.
This has enabled the constant development of better materials, processes and products.
Development programmes and tests ensure that material design and innovation is verified and made valid for industry and customer-specific standards.
In addition, thermoplastic valves are not only corrosion-resistant against most chemicals, but also have a high strength and resistance, are very light and have lower costs than special steels and coated valves.
In addition to this, they guarantee high reliability due to their quality and do not cause any problems over a long period of time.
Devlon® V-API is the leading material behind the engineering solutions required in today’s market, from the oil and gas industry.
James Walker has created in Devlon® V-API, a material that provides protected performance regarding positive material identification technology.
This technology called PMI involves a microscopic additive assimilated into the Devlon polymer that can be identified even by analysing a small sample of material.
In safety-relevant applications such as valves, it is essential that the material indicated matches the material used.

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