
M - C P V
The Bosworth Company
Doc M-09-34-013123
6
M - C P V
Pump Valve Types
TherearetwovalvesineachGuzzlerpump.Onevalveislocat‐
edbetweenthepumpbodyandtheinletport;theother,be‐
tweenthepumpbodyandtheoutletport.YourGuzzlerpump
maybeequippedwitheitherduckbillvalvesorumbrellavalves,
dependingonthepumpoptionschosen.
Theduckbillvalveisshapedlikeabird’sbeak.Whenpressureis
placedontheoutsideofthebeak,itforcesittoclose;when
pressureisplacedontheotherendofthevalve,itforcesthe
beaktoopensothatfluidmaypass.(Figures8A‐8B)Theduckbillvalveon
theGE‐0504xseriespumpsisslightlylargerthanthatontheGE‐0404x
pumps.
Theotherkindofvalveavailableforyourpumpisanumbrellavalve.The
umbrellavalvefeaturesarubbervalvewithaflatrounddiskheldunderten‐
sionagainstaplasticplate(the“valvestop”)thatcontainsanumberofholes
or“pores”.(Figure9)
Whenpressureisappliedtoonesideofthevalvestop,itpushestherubber
diskawayfromtheholes,likeanumbrellaturninginsideout(Figures10A‐
10B).Whenthishappens,fluidoraircanpassthroughtheholes.Whenthe
pressureisreversed,therubberdiskisforcedagainsttheholes,
makingatightsealtopreventanyfluidorairfrompassing.
Eitherkindofvalvecanbefouledbymaterialinthesap(e.g.,
woodshavingsfromtaps,plasticshavingsfromtubing,etc.)
thatistoolargetopassthroughthevalve.Whenthishappens,
thepumpwillbeunabletodevelopanyvacuum.However,
unlikethecaseofadiaphragmfailure,valvemalfunctionwill
notresultinanysapleakingfromthepump.Ifyouwereto
disconnectthepumpfromyourtaplinesandperformthesim‐
plepumpcheckdescribedonpage2,youwouldfeelnovacuumpullingfromtheinletport.Tocorrecttheproblem,the
valveshouldberemoved,inspectedandcleaned.Severalofthestepsinvolvedindoingthisarethesameasthesteps
requiredtochangeadiaphragm.
Valvesaretypicallyreplacedinpairs;i.e.,theinletandoutletvalveofagivenpumpbodyarereplacedatthesameme.
Whenreplacingapairofpumpvalves,itisbestthatonly one valve is removed and replaced before aempng to re‐
move and replace the other valve.
Changing the Valves
1. Followsteps1‐3inRemoving a Diaphragm.
2. OntheGE‐0504Npump,removethe6screwsholdingthe
inletflangetothepumpbody(Figure11).(Note:4screws
areusedontheGE‐0404Npump).Theumbrellavalveislocat‐
edbetweenthisflangeandthepumpbody.
3. Inspectthevalveforanytears.Inspectthevalveporesand
removeanydirtormaterialthatmayhavebecomelodgedin
thepores.InspectO‐ringsforanysignofwearandreplaceas
necessary.Ensurethattheyarecorrectlyinstalledinthe
valvestopgrooves.
Figure 9
GE‐0404xDuckbillvalve
(le:Closed;right:Open)
Figure 8A
GE‐0504xDuckbillvalve
(le:Closed;right:Open)
Figure 8B
GE‐0404xUmbrellavalve
(le:Closed;right:Open)
Figure 10A
GE‐0504xUmbrellavalve
(le:Closed;right:Open)
Figure 10B
Remove6screwsholdingflangetopumpbody.
Figure 11