high temperature Metal To Metal Ball Valve

There are two key points in the design of high temperature Metal To Metal Ball Valves: 1, the correct selection of sealing materials suitable for use at high temperatures; 2, how to compensate the valve in the process of use because of the use of temperature on the valve parts of the influence of temperature deformation.

The operating temperature of the ball valve usually depends on the high temperature resistance of the valve seat material. According to the different materials of the valve seat, the high temperature ball valve can be divided into two types of sealing structures: metal-to-metal (hard seal) and metal-to-non-metal (soft seal). Their common point is that the ball and the valve body are made of high temperature resistant metal materials, the difference is that the former seat is made of metal or heat resistant alloy (such as cobalt chromium tungsten carbide, etc.), the latter seat material is made of non-metallic materials such as para-polystyrene (PPL), flexible graphite and carbon fiber.

High temperature ball valve with elastic sealing structure, due to the reliable sealing performance of various elastic seats and elastic spheres, strong elastic compensation ability, wide temperature range, and suitable for floating ball and fixed ball valve, so it is widely used in high temperature ball valve. Metal to metal elastic seal seat structure

Because the load applied to the seat gasket must exceed the yield limit of the gasket to seal, and the bad thermal cycle will further cause the creep and leakage of the gasket, it is best to avoid the type of seat gasket in the high pressure thermal cycle state. The valve seat is sealed with flexible graphite ring, which has strong pressure resistance, flexibility, plasticity and self-lubrication; And can be well applied to a variety of high and low temperature resistance working conditions. The graphite seal structure is also applied to the valve stem seal structure.

As the main component of the elastic seal seat structure, the spring should pay attention to the following two points:

(1) High temperature will reduce the tempering performance of the spring, (or reduce the hardness) reduce the elastic modulus, cause the use of load and elastic limit to decrease, and increase the corrosion and the ultimate failure of the spring. Therefore, the spring material should use corrosion resistant materials or nickel-based alloys.

(2) In the case of more particle impurities such as coal slurry, the helical spring is easy to fail because of more particle impurities, so in this case, the plate spring should be selected.

High temperature ball valve relative to the general normal temperature ball valve, the valve material selection, structural design and processing accuracy requirements are extremely high. With perfect quality assurance system and process control, Yongjia Dalunwei Co.,LTD produces fully compliant ball valve products.