×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Pump seal frequency is very high

Pump seal frequency is very high

Pump seal frequency is very high

(OP)
Hi All,
I hope this thread will be very interested for some fellow members.
Pump is designed for following conditions.
Inlet temperature 695F
SP,GR at 60 F : 0.95 and at inlet temp: 0.715
Viscosity 0.31 CKS @ 695F
Capacity at inlet temp Normal Design 115 GPM
Capacity at inlet temp: max Design 126
Design inlet pressure is 31 psig
Discharge pressure is 128 psig.
Pump is being operated with following conditions
SP.GR at 60F: 0.59 and at inlet temp:0.477
Viscosity at 100 F 0.17 CKS
capacity at inlet Temp , normal Design 45 GPM
Capacity at inlet Temp, max Design 50 GPM
inlet pressure is killed by installing a level control.
Discharge pressure is recorded more than 150 psig.
22 years are in service and pump seal damaged more than 30 time, pump impeller and pump casing scored heavy rubbing. one time complete impeller and casing also changed. Can someone explain what is wrong with this pump or fluid handling ( I mean service of fluid)

RE: Pump seal frequency is very high

What has the mechanical seal supplier had to say?
Besides the data given, what is the pump style, what is the application, what is the seal failure - any photo's?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Pump seal frequency is very high

(OP)
Artisi,
Centrifugal pump and vertical motor mounted on pump. Pump is for HFO services but used for naphtha service.

RE: Pump seal frequency is very high

Hi MIANCH,
An inlet temperature of 695F is not really a low temperature. The mechanical seal needs to get rid of the heat generated and the pump construction needs to allow for the thermal expansion and prevent heating up the bearings and driver.
Can you give more details on the pump construction? Your description would also fit a close coupled vertical inline pump, which would not be the most suitable for this operation temperature.

RE: Pump seal frequency is very high

(OP)
FMJalink,
These pumps were purchased in 1962, For ADU bottom (HFO services) but in 1998 transfer excess naphtha and off spec kerosene need more pressure to fill naphtha storage tank. 1998 management decided to use this pump for naphtha and kerosene transportation and since the installation and putting in operation, maintenance face seal failure and pump seizing. I know naphtha is getting vaporized and seal is getting heated up / dry as well.

RE: Pump seal frequency is very high

Hi,
May be time to buy a new pump or at least to ask knowledgeable people to have a look (pump manufacturer and/or mechanical seal vendor)?
Over the time, wears appear.
Good luck,
Pierre

RE: Pump seal frequency is very high



22 years running with a seal failure once a year in average is not a ban number... I think that clearance into internals are grater that allowed...Time to change the pump

Lifetime for pumps refinery services is around 15 years, your economical analyst will give you the figure is changed is an option against the maintenance cost. 

horacio

https://www.linkedin.com/company/lagotuy/

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close