速度突變會產(chǎn)生沖擊壓力波傳遞，傳遞速度很高，可以使閥出口段壓力升高至額定壓力的數(shù)倍，這就是管路中的水錘現(xiàn)象，它可以導(dǎo)致閥或管道破裂，產(chǎn)生事故。為了避免這類事故，目前人們都是采用具有延遲關(guān)閉特性的閥門，如兩階段控制關(guān)閉蝶閥、具有子母閥板的水力控制閥、緩閉止回閥等。

　　有必要設(shè)計一種裝于旁通管路上的自動泄壓閥，它可以在泄壓時間內(nèi)將回流引至泵進口，即泄壓回流不再通過泵轉(zhuǎn)子部件，完成泄壓能自動關(guān)閉，*解決了泄壓回流沖擊泵反轉(zhuǎn)的問題，并達到有效消除水錘的目的。

普通防爆電磁閥EFG551H401MO
8210C93N     8342G001      8316G24MO    NFG551A401MS
WBIS8223A310 WBIS8262A386  WBIS8316A381VWBIS8316A384V
8262G13      8263G206V     EF8308741F   EF8308B40
EF8320G174   EV8327G52     EV855G455    18900001
35500382     54191006      EF8344G70    8344G72
NFG551B402MS 8210G2        54190017     13100156
EFHC8210G11  EFHC8210G13   EFHC8210G3   8290AO34
WBIS8314A300MO 88100142    EV8316G384V  8210G95
8342G001     WPTISB307A406 V8316G384V   EFG551G417MO 
NFB551B401   EF8320G18     54100883     55102005
55102009     55102011      EF8300D61U   43004422
U8325B39V    SCE238A007    43004166     NFB316A54
55192005     E238A207      34207093     EF8025B224
HT8316G074   12100309      34203086     8345G1

普通防爆電磁閥EFG551H401MO
19200001     8210G13       8321G1       EF8300D61U
SCG531B001MS 8262G80M0     EF8320G188   EF8342C1
43550447     55192009      55192011     EV8316G82

HT8316G74    E290A005      EF8025A224MO 8262G019
NBXB210B038  8320G200      NF327A011    SC8551A001MS
SC8551A017MS 43004158      8223G021     8360G071
EF8210G094   EF8210G056    EF8210G095   SCE210C094
WT8551A1     SCG353A040    SCG353A050   SCG353A060
EF8327G2     NFB327A011    8323G3       8320G202
34203087     35500333      52000008     U8325B14V 
8316G66      NFB320A200    EFHC801bG1   EFHC8321G2
HB8320G200   HBXB320A200   HT8316G66    NF8320A200
EF8551A001MS EF8210D089V   EFG551417MO  8316G24MO
EFHC801bG1   EFHC8321G2    HB8320G200   HT8316G66
NF8320A200   EFL8344G70    8320G13      52100004
8025D224     SCG353A044    EF8342G003   SCE238A005
8342G1       35500343      35500344     35500346
SCG238C017   8210G95HW     SCG353A043   U8325B39V