1. Product Structure & Classification

The pneumatic diaphragm control valve consists of two core components: a valve plug and a valve body (including the valve seat). According to different working conditions, it is available in three structural types: straight-through single-seat valve, straight-through double-seat valve and high-pressure angle-type valve.

The straight-through single-seat valve features low leakage rate. However, the fluid thrust produces a large unbalanced force on the plug. Therefore, it is suitable for working conditions that require low leakage, small pipe diameter and low pressure differential across the valve.

The straight-through double-seat valve is designed with upper and lower valve plugs. The fluid thrust acting on the two plugs is opposite in direction and largely offset each other, generating a small unbalanced force. This structure allows a large pressure differential between the valve inlet and outlet. Nevertheless, it is susceptible to severe erosion under high differential pressure and is not applicable for media with high viscosity, suspended particles or fibrous substances.

The high-pressure angle-type valve adopts a right-angle valve body with a simple flow path and low flow resistance. It effectively resists erosion caused by high-speed fluid. It is especially suitable for fluids with high pressure differential, high viscosity and suspended particles, as well as gas-liquid two-phase media prone to flashing and cavitation.

2. Technical Parameters