A Double-flanged butterfly valve, as the name implicates, has flanges welded to its body - one at the upstream end of the valve and the other at the downstream end of the valve. This type of butterfly valve, used to control, regulate and throttle flow, is the most resilient seated valve design which is usually used for dead-end service.
A Double-flanged butterfly valve is easier to mount and center, and is also mechanically stronger in construction than lug or wafer design, making it suitable for heavy-duty, large flow-handling scenarios.
Huamei’s Flanged-end valves permits easier installation and removal from pipeline as it is bolted to the mating flanges of other pipes. Huamei will walk you through installation on the proper installation of double-flanged valves to prevent misalignment, which will cause long-term problems in your piping systems.
Huamei’s Double-Flanged Butterfly valves is internationally compatible with other world flange standards such as ASME and ANSI classes such as pressure classes 150, 300, 600 and DIN ISO PN16, PN25, PN40, PN100. This promotes easy installation, alignment, and safe usage as these valves can be used in many different industries.
Construction of Huamei Double-Flanged Butterfly Valve
How is it made/Manufacturing of Double-Flanged Butterfly Valves
Huamei fabricates Double-Style Butterfly Valve in a variety of materials of construction. The construction of this butterfly valve ensures that the following are fulfilled:
- Quarter-turn operation
- Ability to perform as a shutoff valve
- Restriction can be performed almost accurately
- Allow dead-end service or removal of downstream piping
Furthermore, Huamei made certain that common valve problems are not left unanswered by designing and fabricating state-of-the-art Butterfly Valves, with extensive research and efforts of their in-house professionals, experts and engineers.
Double-Flanged Butterfly Valve Basics
Seat, Disk and Stem of a Wafer-Style Butterfly Valve
The disk is the flow closure part of the butterfly valve, bored in the middle to receive the stem. The usual method of securing the disk to the stem is by bolts or pins.
Huamei, however, does an alternate method involving shaping the upper stem bore to fit a squared or hex-shaped stem. This method is advantageous in corrosive applications and ensures uniform sealing as the disk is allowed to float and seek its center in the seat.
The stem extends beyond the bottom of the disk and fit into a bushing in the bottom of the valve. Huamei designed different material bushings to suit differences in chemical properties of the media being handled by the valve. Stem seals are made of O-ring seals. For corrosive substances, Huamei designed the valve stem in such a way that it cannot be in contact with the material being handled. This is to protect the valve stem from degradation and possibly failing the valve system.
The seat utilizes an interference fit between the disk edge and the seat to provide shutoff. The material of the seat can be made from many different elastomers or polymers. The seat may be bonded to the body or it may be pressed or locked in.
In high-performance butterfly valves, the shutoff may be provided by an interference-fit seat design or a line-energized seat design, where the pressure in the pipeline is used to increase the interference between the seat and disk edge.
The most common seat material is polytetrafluoroethylene (PTFE) or reinforced PTFE (RTFE) because of the wider range of compatibility and temperature range.
Metal seats are also offered in high-performance butterfly valves. These metal seats allow a butterfly valve to be used in even higher temperatures to 1,000 Degrees F.
Fire Safe Seat
Fire-safe designs are offered that provide the shutoff of a polymer seat valve before a fire, and the metal seal backup provides shutoff during and after a fire.