Description
All the rubber-lined butterfly valves are of high reliability, and robust design in accordance with the worst prevailing ambient conditions.
Ebonite lining: has good chemical stability, excellent chemical corrosion resistance, organic solvent resistance, low water absorption, high tensile strength excellent electrical insulation, etc. features.
This product is derived from the double eccentric butterfly valve of our company. It also has superior performance and security. Plus the bypass system’s unique advantages, it’s more and more popular with clients around the world.
It consists of the main valve， the integral bypass pipe, and the bypass valve.
When closing the valve, close the main valve first and then the bypass valve; When opening the valve, first open the bypass valve, then the main valve. In this way, to balance the differential pressure between upstream and downstream, the main butterfly valve can be opened and closed easily.
Valve Body
The bodies are constructed of ductile cast iron, with double flange ends in accordance with EN1092-2(other standard drilling be provided as special request)
Valve Disc
The flow-through disc design is employed to minimize line turbulence and lower head loss. The greater free flow area provides less pressure drop in the full-open position than other disc shapes. The material of ductile iron and stainless steel are available.
The internal and external coating(FBE) in 250μm DFT is corrosion and abrasion-resistant, suitable for use in drinking water, treated wastewater, raw water, etc.
The valves have position indicators and adjustable end limit stops at both open and closed-end positions to prevent damage by excessive operating force. They shall close clockwise. For underground valves, the position indicator will be extended above ground.
The gearbox operator is worm wheel type and has a self-locking function. If necessary, the spur gear/bevel gear is equipped to reduce the required input torque.
All the valves are designed for no leakage underflow from either direction tested at a differential pressure across the seal of rated working pressure. Each valve is subject to a body strength and seat leakage test of separately 1.5 times and 1.1 times the design pressure according to EN12266 before leaving the workshop. A test certificate is to be submitted.
