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

Mechanical seal failure flow rate calculation

Mechanical seal failure flow rate calculation

Mechanical seal failure flow rate calculation

Hi All,

I am fairly new in terms of dealing with Mechanical Seal and would like to know how I can calculate the flow rate if the seal fails. I have attached a picture of a mechanical seal that I am working with.

RE: Mechanical seal failure flow rate calculation

you cannot calculate this. rather strange set up, you have a fixed and a floating bush? normal seal leakage is approx 5-10cc/hr. are you injecting N2 where the green arrows are? normally there is only 1 bush and this appears to be for safety because the product is not environmentally safe when it leaks. if thisi s the case then you have the wrong seal. one needs to know what the produst is, if you have a high Vapour Pressure then you will have a gas leak, if low VP then liquid leakage. so you question is not clear, do you want to know what the max leakage is in the event of a seal failure or normal leakage?
send some more information about product and what you are trying to achieve.

RE: Mechanical seal failure flow rate calculation

I would have liquid ammonia at the red arrow if the seal failed. I would like to know the max leakage at the event of a failure.

RE: Mechanical seal failure flow rate calculation

Define fail. Your valve is 100% functional to 100% failed. You could calculate the flow rate without seals to determine max leak rate. Then you will know you will be between this number and zero.

RE: Mechanical seal failure flow rate calculation

Max leakage in the event of failure needs to define the mode of failure. Looking at the drawing there are no pressures shown but if we assume flow through a 1/2" pipe with 1/8" orifice and 20PSI Delta P then leakage is around 1.5Gal/min. orifice area represents the bush clearance but the leakage depends on the level of damage. i think that you need to have a dual pressurised seal anyway for safety. I remember years ago getting a whiff of ammonia and it was not pleasant. if this were mine i would convert to double pressurised seals.

I now understnad why you have a double bush configeration which is rather unusual in fact this is the first time i have ever seen it. I think it is used like this to minimise any leakage to atmosphere in the event of a seal failure. not the best way to seal this if you are after safety.

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


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