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Foreword:

The silent check valve is applied on lift pipe or fluid pipe with pressure. The valve gate, with restoring force, will be closed at suitable speed when pump is shut down to separate the collision and noise between the inertia fluid (positive pressure) and the back flow (negative pressure) caused by power off. The silent check valve plays an important role on piping, especially applied on the outlet of the pump. The silent check valve applied on the outlet of the pump should be selected carefully, and it must be able to resist the highest pressure, the largest water hammer effect and the biggest fluid impact. If the silent check valve is not good enough, when silent check valve is damaged, it will cause the fluid flowing back and losing pressure or, more serious, the damaged parts will fall on the blades and damage the pump seriously and, hence, loses more money. To avoid the defects mentioned above, our company manufacture a more practical and economical model, called " FULL OPEN STYLE SILENT CHECK VALVE"

Model:CHF
 Features:
  • The design of the valve is full flow lift type and water flow does not directly push the valve gate. Hence, the valve can work for a long time and have huge flow rate.
  • The design of plug is hang type and automatically locating. It can adjust the close position of the plug no matter high or low pressure.
  • The design of plug is semi-round and can resist higher pressure.
  • The design of sealing is upside-down of "V " and it is suitable for high and/or low pressure condition. And the tightness of the valve gate is best.
  • When the pressure is high, plug and seat work together to prevent the sealing from being pushed by the high pressure to lengthen the longevity of sealing.

Item Material
Body Cast iron Stainless steel
Bypass valve set Brass Stainless steel
Plug Brass Stainless steel
Seat Brass Stainless steel
Locating bolt NBR Stainless steel
Cantilever Brass Stainless steel
Spring Stainless steel Stainless steel
Pin Brass Stainless steel
Sealing retainer Brass Stainless steel
Sealing NBR NBR
 
  • Test pressure:
    Stainless Steel-35kgf/cm2
    Cast Iron-21kgf/cm2
    Ductile Iron-35kgf/cm2
  • Applied temperature: -15℃ ~ 80℃
  • Vertical and horizontal installation is acceptable.
  • The bypass valve set won't be attached if the diameter is larger than 6 inches.
  • 口徑8"以上,不鏽鋼材質閥體不附
    旁通閥門組
Size Connection type H A
2" Flange 183 122
2.5" Flange 200 132
3" Flange 210 147
4" Flange 220 160
5" Flange 260 180
6" Flange 280 200
8" Flange 370 --------
10" Flange 450 --------
12" Flange 520 --------

全開型靜音逆止閥流量方面的改善

  The Improvement of Full Open Style Silent Check Valve on Flow Rate
 The full open style silent check valve adapts the lift open style plug and the plug has hidden bypass design, which will bring the smallest flow resistance inside the valve body. When fluid flow through the valve, and hence, will reduce the loss of pump running effect and improve the power efficiency. Since that, the defects of traditional silent check valve, e.g. many turning points, large resistance, not smooth flow way and fluid impact the valve directly and shorten the valve life, have been improved.
 

   
Full Open Style Silent Check Valve    Traditional Silent Check Valve

Full Open Style Silent Check Valve Flow Chart


The comparison of CV values between Full Open Style Silent Check Valve and Traditional Silent Valve


Q = Rate of flow (GPM)
△P = Pressure drop
across valve (psi)
S = Specific gravity    
of fluid (Water=1)
1 Gallon =3.785 Liter
  2" 2.5" 3" 4" 5" 6" 8" 10" 12"
Z Tide full open type 180 270 410 720 1050 1615 2865 4025 5700
'Traditional type 70 105 155 275 435 625 1115 1770 2500

The Improvement of Full Open Style Silent Check Valve on Pressure-Resistance

活動懸吊式自動定位閥門設計:

The hang type plug design can match sealing of the up-side-down " V" type sealing. It can adjust the closedown position of the plug and seat, no matter the pressure is high or low, and won't be affected by cantilever.
 
  The full open silent check valve adopts the round-arch type design. After the mechanics calculation and fluid pressure model test, the performance is excellent.
 
低壓時閥門密合情形

高壓時閥門密合情形
     

The special design of the up-side-down "V" sealing of the full open silent check valve can offer the best closedown performance when the valve is close (as shown on the figure). When the fluid pressure is low, the sharp end of the up-side-down "V" sealing will double-close down with seat.

If the fluid pressure increase, when the plug presses downward, the sharp end of the up- side-down "V" type will develop outward to increase the attached area of the rubber.
 

Under the high fluid pressure situation, the full open silent check valve will close its plug and seat via metal-to-metal type (shown as the figure) to prevent the sealing over-pressed to become fatigue.

At the same time, the up-side- down "V" type sealing develops outward to perform an excellent closedown (shown as the figure).

不容忽視閥門所須承受的施力

流體在於閥門上的施力 = 閥門截面積 * 流體壓力
例:6"逆止閥關閉時,流體壓力10kgf/cm2
則流體在於閥門上的施力為:閥門直徑約170mm(17cm)計算。
流體在於閥門上的施力=(8.5cm) *3.14*10kgf/cm2 =2268.65kgf
可以說是,當管內流體壓力10kgf/c m 2 時,有2268kg的力量施加在閥門上如果以動壓再加上水錘現象產生的衝擊力將更大。


探討傳統逆止閥的閥門於高壓狀況可能的影響

傳統無聲逆止閥

         (圖一)
       (圖二)
(圖一)
若閥門座與橡膠閥門墊片的密合點較尖銳時,閥門蓋承受流體正向壓力的壓的壓迫,導致橡
膠閥門墊片彈性疲乏或因剪斷作用的影響而斷裂。
另外,閥門蓋在高壓情況下亦可能產生中央向
下凹陷的變形,終使傳統靜音逆止閥喪失功能 。
  (圖二)
若閥門座與橡膠閥門墊片的密合點較平坦時, 閥門墊片易受側向壓力的擠壓導致橡膠閥門墊片彈性疲乏與變形。
及墊片支座的變形。另外,閥門座與閥體之間,如圖所示的結構,亦較易有沉澱物淤積,嚴重時可能導 致閥門密合不良。
 
★上述情形亦可能同時發生,由此可知閥門耐壓性的設計,在逆止閥來講非常重要 。

Z-Tide Valves Industrial Co.,Ltd TEL: +886-7-331-1060 FAX: +886-7-331-0100 E-mail: sales@z-tide.com
Official Exporting Department: Elite Line Industrial Corporation
Z-TIDE Group Elite Line Industrial Corp
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