5 stage barrel type horizontal centrifugal boiler feed water pump got seized during laser alignment. What could be reason ? Shaft on DE & NDE was kept aligned by chain blocks. One maintenance guru says that it could be due to reverse rotation during alignment. According to him , seizure is due...
I have seen Turbine maintenance guys scrapping the bearings (supposedly) for oil wedge. Is there some systematic calculations for scrapping or it is just operating experience among turbine maintenance gurus ? I have worked on large pumps and motors. We donot do it and we rely on designer's...
Degraded elbow that needs replacement
OD : 529mm
ID: 509mm
t: 10mm
(Measurements roughly taken)
I am not well known to this work. I donot find this elbow size in ASME 16.9.
Daren!
There is perpex glass jar installed on the top of the acid storage. Glass jar contains silica gel. With the passage of time glass jar surface has become opaque( not clear). Now we have dismounted the glass jar but are clueless to clean it. Pls guide
Daren!
Vendor has not provided torque for gland tightening of 10' control valve. Is there can be any rough idea for torque gland tightening? Many 10' valve gland tightening torques that I know vary from 20Nm to 30Nm depending on bolt size.
Daren!
On our site, 45KW motor is installed instead of 37KW (Pump EMR , Name plate data suggests) since commissioning. This motor-pump unit has experienced increased vibration issues for previous 10 years. Can the increased KWs of motor cause vibrations in pump-motor unit?
Daren!
There are two identical PD (gear) pumps installed. Both feed lube oil to boiler feed water pump in stand by condition. It is interesting to note that discharge pressures (pressure guage installed before check valve) on both pumps before check valve are same one they are taken independently in...
thread821-498052
I have recently worked 04 vertical pumps. In older pump, there is no thrust bearing in pump. There are only hard rubber/graphite (BBF6) guide bearings. On NDE side of motor, Spherical taper roller bearing is installed to cope downward thrust. On DE side, deep groove ball bearing...
In vertical multi stage condensate pump drawing, guide bearing has fit 120H8/f9. When I calculate it is clearance fit with
Min clearance: .036mm
Max clearance: 0.177mm
Where as in Pump instruction book of same vendor, nomianal clearances for guide bearing are as under
Min clearance : 0.15mm...
In vertical multi stage pump drawing, guide bearing has fit 120H8/f9. When I calculate it is clearance fit with
Min clearance: .036mm
Max clearance: 0.177mm
Where as in Pump instruction book, nomianal clearances for guide bearing are as under
Min clearance : 0.15mm
Max clearance: 0.4mm
Kindly...
We have experienced increased water content in lube oil of main feed water pump. This lube oil is supplied by shaft mounted main oil pump from lube oil tank to bearings of main boiler feed water pump and main boiler feed water booster pump. Both pump are coupled in series by motor and reduction...
We have 4 stage boiler feed water pump and it uses plan 23 for mechanical Seal. After necessary maintenance, pump was taken on recirculation line. I observed the temperature of return water to heat exchanger ( heat exchanger used in plan 23 for mechanical Seal) was higher then adjoining running...
In Fisher control valve, there is no OEM instruction to pre-tension the actuator spring by rotating the handwheel before calibrating the actuator travel against pneumatic pressure. Is it right practice to pre-tension the spring ?
Daren!
Threads on shafts on some pumps are not fully threaded on position where lock nut engages on pump shaft to contain sleeve or bearing . Kindly see pic in link. What is the reason of keeping flat (unthreaded) portion on pump shaft which lock nut engages with shaft...
Theoretically, axial thrust in double suction closed impeller centrifugal pump is zero. But vendor always recommends 0.15mm-0.20mm axial clearance on non drive end side of pump. Why is it so? Does double suction centrifugal pump feels thrust due to motor and if so then why?
Daren!
Fisher control valve introduces diagonal pin that passes from plug into stem. Does it not weaken the valve stem and compromise the cushion for misalignment provided by threads?
Daren!
I have seen three times that Plug has been detached from stem of pneumatic control valve. There are three provisions for plug and stem connection.
1. Plug has threaded hold in which thread stem passes through.
2. There is provision of Nut at the end of stem. This but seats on the plug and holds...
My question that we generally keep the axial float of centrifugal pump on drive end of motor due to coupling cushion between pump and motor shaft. Is it right practice? What could be disadvantage if we keep float on NDE side of motor.
