OH3 vs OH4 2

[hemvig]

OH3(flexible coupling) VS OH4 pumps (rigid coupling),
API 610 states "it doesnot meet all the standards of the OH4 pump"...

Can someone specify what are the disadvantages of OH4 type pump over OH3.

Thankyou

 

[TenPenny]

centrifugalpump.org/pump_API_designation1.html

has a good description and brief discussion that should exactly answer your question.

 

[ione]

Check ISO 13709, there is a table (no. 3) listing special design features for OH4. If the pump is not manufactured according to those special features the pump doesn’t meet International Standard

 

[PumpSmart]

OH3 AND 0H4 ARE VERTICAL IN LINE PUMPS AND THEY RUN WELL IN SOME APPLICATIONS
THERE ARE SOME MAIN DIFFERENTS.
ONE OF THEM IS THAT OH3 IS FLEXIBLE COUPLED BECAUSE DOES NOT NEED TO BE RIGID. SINCE THEY HAVE A BEARING HOUSING (WITH RADIAL AND THRUST BEARINGS) THAT CAN ABSORB HYDRAULIC LOADS (IT MEANS RADIAL HYDRAULIC LOADS AND AXIAL HYDRAULIC LOADS). SO IN OH4, SINCE IT IS RIGID, BEARINGS MOTOR SHOULD CARRY THOSE LOAD REDUCING MOTOR BEARING L10 LIFE.

HIGH TEMPERATURE, SINCE YOU HAVE A BEARING HOUSING, IT IS PROBABLY TO HAVE MORE OPTIONS FOR LUBRICATION, HIGH GREASE TEMPERATURE, AIR PACKET IN BEARINGS, SUMP IN DEPTH, OIL WITH WATER COOLING, ETC. AND HAVE MORE ROOM TO DISSIPATE AS FUNCTION OF CONDUCTION, CONVECTION AND RADIATION THAT CAN HANDLE IN BEARING HOUSING THAT IN DIRECT/RIGID COUPLIN.