Exploring the innovative features and engineering principles of Severn’s OCT TOV Butterfly Valve that puts safety first.

Not only is this projectile a huge safety concern but has the potential to compromise the pressure envelope of the valve allowing process to escape into the atmosphere.   

Severn has designed all their Triple Offset Butterfly Valves as standard with anti-blowout incorporated at both ends of the valve. This negates any chance of the shaft blowing out if the pins were to fail. The reduced shaft diameter at the drive end ensures the shaft cannot blow out through the packing follower.

On the blank end of the valve, Severn have multiple features which prevents shaft blowout. The anti-blowout ring on the threaded shaft end ensures positive engagement without the need for additional fasteners. The blank end plate is locked in place and is designed to withstand full rated test pressures.  

Dual anti-blowout devices are standard on the OCT TOV Butterfly Valve, meaning that even if the gland is removed, the secondary internal anti-blowout device will stop ejection of the shaft under the pressure, thus increasing both operator and plant safety. 

Severn have designed their Triple Offset Valves to exceed the minimum wall thicknesses stated in ASME B16.34. Instead of just using the minimum allowance, Severn have gone above and beyond to ensure the safety of our products in the field for our customers.  

Within Severn’s Triple Offset Butterfly Valve is a corrosion allowance. This means that the valve can afford to concede material to corrosion over time without affecting the pressure containing integrity or safety of the valve. The amount of corrosion may vary depending on the environment the valve is working in, but due to Severn’s engineering heritage and excellence, the OCT TOV Butterfly Valve has been designed to withstand changes in working environments and process conditions.  

High MAST figures and safety factors are key when designing the Triple Offset Butterfly Valve. MAST is the Maximum Allowable Shaft Torque a quarter turn valve shaft can withstand during operation without mechanical failure. With Severn using higher MAST figures on their Triple Offset shafts, this helps maintain the structural integrity of the valve.  

Sizing actuators correctly is a credit to Severn’s engineering excellence. Actuators, gearboxes, or any form of obturator that drives a quarter turn valve must be sized correctly by using the correct input and output torques. By torque testing the physical products prior to final inspection, we can compare the physical torques against our theoretical torques to maintain accuracy and consistency across the range.  

Safety has always been at the forefront of Severn’s designs, and this is paramount in the 8500 Butterfly Valve range.