Adanac’s top entry ball valve

Adanac have been involved in cryogenics since 1986. Over this time period Adanac had developed an understanding of how materials behave and perform at such extreme temperatures and applied this scientific understanding to developing a valve product suitable for use with cryogenic applications.

The emergence of the LNG industry in recent years has seen a rapid increase in demand for equipment. This demand has often allowed for substandard products to be used in critical applications due to a lack of availability for suitable equipment. This obviously creates a safety issue. Certain valve manufacturers offer valve products which they believe are suitable for use at cryogenic temperatures, but in essence all they are offering is a standard valve with extended bonnet. In reality, extensive knowledge of cryogenics is required to ensure a valve is supplied suitable for low temperature use. However, availability is not the only avenue used to supply substandard product. Just as in so many other industries, cost is also a dominant factor. Whilst this is understandable to a certain extent, safety must not be compromised.

In recent years, site and contractor specifications for valves used with LNG have insisted upon top entry design ball valves. Whilst project procurement allow for substantial lead times, emergency maintenance and end of project requirements remain a problem for site engineers, as valve manufacturer lead times are often quoted in months not weeks!

The design of the top entry ball valve lends itself to critical applications. The valve body is manufactured in one piece design, minimising leak paths, whilst allowing for in-line maintenance of the valve through the bonnet without removing the valve body from the pipeline. This means that replacement of the valves seats and seals can be done with relative ease. The one piece body design, coupled with butt weld end connections, ensures that there are no mechanical joints in the pipeline as there are no pipeline stresses on the bonnet connection. This design is favoured by engineers and maintenance personnel alike and is now the preferred valve type for the LNG industry and other Firesafe applications.

Due to the close relationship between the top entry ball valve and the LNG industry, Adanac has worked very closely with American manufacturer Conbraco over the last year to develop a firesafe valve for cryogenic service. With our manufacturing capabilities, Adanac can offer delivery times from 4 working weeks for firesafe and cryogenically tested top entry ball valves. We achieve this by converting “standard” off the shelf Apollo top entry ball valves to extended bonnet for cryogenic duty down to -196oC, using cryogenic extended bonnet conversion designs such as BS6364:1984 and end user specifications such as Shell 77/200. A service regularly utilised by LNG facilities globally including Grain LNG, RasGas and Egyptian LNG. Adanac’s in house low temperature test facility allows modified valves to be subjected to prototype and production testing at temperatures down to 196oC in accordance with National standards such as BS6364:1984 Appendix A and user standards such as Shell 77/20 or 77/306.

The modification of valves for cryogenic use has provided a solution to supply problems for a large number of LNG facilities, but it also raises the inevitable questions regarding quality and reliability of product supplied. In addition to Conbraco, Adanac work closely with some of the world’s largest and most respected valve manufacturers, such as Kitz, OMB, Bonney Forge, Neway, Hindle and Flowserve,all of which authorise us to modify their product, and insist upon Adanac working to the most stringent of production and test specifications.

The global expansion of the LNG industry in recent years has provided economic growth opportunities globally, but whilst supply may be struggling to keep up with demand, and the inevitability of finance playing a pivotal role, quality and safety cannot be allowed to be compromised, at any cost.

Adanac Valve Specialities Ltd
Tel: 01359 240404
Website: www.adanac.co.uk

Published: 28th November 2011