Butterfly valves for extreme and hazardous conditions

Paul Boughton
Tomoe Valve Limited, a global leader in the design and manufacturing of valves and process control systems, has enhanced its revolutionary 847T range of chemically resistant butterfly valves as part of the company’s ongoing product development programme.

The extended 847T range benefits from improved sealing performance and strength, and minimal torque under hazardous conditions.

The Tomoe 847T range is used across a wide spectrum of industries including chemical processing, water treatment, food processing and vehicle manufacture. 

The construction of the new Tomoe 847T range provides superior strength and unique sealing properties essential in applications where conditions are potentially hazardous such as, chlorine, gas, corrosive acids, steam, brines and high purity systems. The range is also suitable for cooking oils, cooling water systems and vehicle paint plants.

The seat construction was designed and developed to ensure that there is no mechanical bond between the rubber seat support and the Teflon lining material, eliminating problems of separation and high or variable torque caused by expansion of the lining. As a result, the new range provides stable conditions during the valve operation.

Manufactures using an injection moulding method and utilising the properties of Teflon at a minimum thickness of 3mm, allows the seamless construction of the 847T valves. This seamless lining delivers complete stability in all conditions including temperature cycling. It also eliminates common problems that occur with conventional valves, where permeation of fluids and gases, particularly at high temperatures, can occur.

The upper and lower stem housings of the 847T range have the same length, high tension coil springs, which provide equal and consistent loading on the sealing mechanism, important under variable temperature conditions. Total sealing in the valve structure is achieved by primary, secondary and independent tertiary seal, through the gland packing design. There is also a fourth seal of dust seal O-rings on the top and bottom shafts.

Also available from Tomoe is a specialist range of actuation packages that are ideally suited to match the operating requirements of the 847T range of valves. The unique seat and sealing properties of the 847T products ensure low and consistent torque figures to be maintained and eliminates the effect of ‘disc set’. This occurs when valves are held in the closed position for long periods of time and the lining sets around the edge of the disc.  These features make the 847T range ideally suited to remote and power operation.

Part of Tomoe’s product development initiative to continually enhance products in line with the changing demands in industry, Tomoe continues to be at the forefront of valve and process control systems with design features and materials technology.

For more information, visit www.tomoeeurope.co.uk