China · Xinhui Valve Co., Ltd.Phone: 0577-57760066 57760077
Address: Xiaojingyu Industrial Zone, Qiaoxia Town, Yongjia County, Zhejiang Province
最小流量的自动再循环 Pump protection valve for automatic recirculation to protect the minimum flow of the pump
Pump protection valve (automatic return three-way valve, TDM type minimum flow valve, automatic recirculation valve)
用于保护离心泵，防止泵在低流量工况下由于过热、严重噪音、不稳定和气蚀而引起的损坏。 Automatic recirculation valve is used to protect the centrifugal pump from damage caused by overheating, severe noise, instability and cavitation under low flow conditions.
Operating principle of automatic recirculation valve
According to the different main flow, the main valve disc of the recirculation valve will be determined at a certain position. The stem of the main non-return valve will transmit the main valve disc action to the bypass through a lever. At the same time, the flow of the circuit reduces the pressure to the required value at the outlet. When the main valve disc returns to the seat closed state, all flow passes through the bypass (return). When the main valve disc rises to the top position, the bypass is completely closed and all pumps Flow goes to the process system.
Connection method flange standard according to DIN or ANSI, other standard flanges, such as: ISO, BS, JIS, NF, etc., can be provided on request.
The inlet and outlet connections can also be welded.
The bypass connection method is only flange connection (easy to check).
Material Standard body material: W. -Nr. 1.0460 (C22.8) (ASTMA105).
The material of internal parts of TDC valve is standard stainless steel with a minimum chromium content of not less than 13%. The control sleeve, sleeve base and eddy current cone are all surface treated (ion vacuum hardening) to resist wear.
Other forged materials for valve bodies and internal parts are available on request.
The choice of valve body material is determined according to the pressure and temperature conditions.
All valve bodies combine four functions in one
|Size-encoding||Pressure rating-coding||Connection method-coding||Structure-coding|
|DN80 (3 ”) = 10 DN100 (4”) = 11 DN125 (5 ”) = 12 DN150 (6”) = 13 DN200 (8 ”) = 15 DN250 (10”) = 16||PN100 (600lbs) = 6 PN160 (900lbs) = 7 PN250 (1500lbs) = 8 PN320 = 9 PN400 (2500lbs) = 0||F = DIN standard flange U = ANSI standard flange S = welded port||V = vertical installation H = horizontal installation W = larger size bypass CS = carbon steel (W.-Nr.1.0460), ASTM A105|
|01||Lower valve body|
|02||Upper valve body|
|03||Stem guide bracket (upper)|
|03.1||Stem guide bracket (lower)|
|07||Check spool assembly|
Install the automatic recirculation valve as close to the centrifugal pump as possible, preferably directly at the pump outlet. The distance between the pump outlet and the valve inlet should not exceed 1.5 meters to prevent low frequency water hammer caused by liquid pulsation. Priority is given to vertical installation and horizontal installation is also possible. Due to the solid design of the TDC valve, it has low noise and high reliability. Maintenance and installation instructions are provided on request. During the routine weekly inspection of the pump, the prescribed function of the valve should be checked at the same time.
●减少设计工作量(四种功能集于一体); ●减少安装和维护成本(自力式,不需外部能源); ●减低故障发生的可能性—将高速流体造成故 障的可能性减至最小,没有气蚀问题和电器接线费用; ●低流量工况下仍然可以保证泵稳定性; ●与常规系统相比,整体费用低。 ● The bypass does not require continuous flow and reduces energy consumption; ● Reduces the design workload (the four functions are integrated into one); ● Reduces the installation and maintenance costs (self-supported, no external energy required); — Minimize the possibility of failure caused by high-speed fluid , no cavitation problems and electrical wiring costs; ● pump stability can still be guaranteed under low flow conditions; ● compared to conventional systems, the overall cost is low.