Attached is an SMath Sheet that I developed to verify check valve sizing. I am looking for some help to

1. define the symbolic equation.
   
2. programing (which I admit I am terrible at).

Any and all "optimization" or better way to get this done is encouraged
Thank you Check Valve Sizing.smz (15 KiB) downloaded 48 time(s).

OK. Figured out the item 1 ... programing (item 2) help please
Check Valve Sizing.smz (14 KiB) downloaded 50 time(s).

Deae ElSid:

In the attached file , you will find the solution I propose.

My best Regards


Carlos


Check Valve Sizing_CBG.sm (47 KiB) downloaded 51 time(s).

You size "Control valve". Check valve is an ON-OFF switch [open or close] to block return.
Differently, Control Valve is a variable restriction [rougly a variable ON-OFF switch].
Chek valve is a flapper inside the pipe. Infinitely speaking, it has linear losses, but ignored
in piping design. We only consider the unrecoverable "singular losses". The part of the linear
losses is finally consumed and adds to the singular losses component.

Jean

No, I dimension a swing-type check valve , according to the methodology of " Flow of fluid through valves,
fittings , and pipe , "Crane" , technical paper No. 410 , which is to ensure that the speed through
the selected valve , is greater than or equal to that required for the check valve fully open work .
If the methodology is correct or not , is outside the scope of the calculation ,
and I did agree to support requested by Mr. Elsid only


Best Regards

Carlos

If the speed is enough to full lift indicates nothing.
Speed at horizontal or vertical installation won't be the same.
If you have to cross check final a project, do some pertinent
minimum mass flow rate wrt the supplier valve data.
More puzzling is the Bernoulli redude/expand associated with
a check valve ... for sure I have never seen that !

My version (no programming)

Check%20Valve%20Sizing_MK.smz (14 KiB) downloaded 41 time(s).

By the way, the calculations seem to be incorrect WRT speed, as well as resistance coefficient K (according to the source of methodology - Crane tech paper 410):
chapter 2 "Resistance Coefficient K, Equivalent Length L/D And Flow Coefficient" states, that

Quote

... the resistance coefficient K is always associated with the diameter in which the velocity in the term v²/2g occurs. The values in the “K” Factor Table are associated with the internal diameter of the following pipe schedule numbers for the various ANSI Classes of valves and fittings ... When the resistance coefficient K is used in flow equation 2-2, or any of its equivalent forms, the velocity and internal diameter dimensions used in the equation must be based on the dimensions of these schedule numbers regardless of the pipe with which the valve may be installed

So, using pipe sizes as in the calculation, is incorrect. The resulting head loss is wrong.

I'm not familiar with the rules used in America, our country's standards differ much, but the general physics principles should stay the same on the both sides of the ocean?

Corrected: Check Valve Sizing corr_MK.smz (14 KiB) downloaded 48 time(s).
So, the corrected calculation results in different selection: 18 in instead of 16.

Thank you guys.
I will take a look. This came directly from one of the examples in the Crane Manual. I think I need a NEW version with all the addendums and issues I keep finding. My version is from 4/10 reprint ... April 2010. What versions are you using?

Wrote

I will take a look. This came directly from one of the examples in the Crane Manual. I think I need a NEW version with all the addendums and issues I keep finding. My version is from 4/10 reprint ... April 2010. What versions are you using?

I used v. 2009 - but it hasn't been updated since then, all later versions are exact reprints (except one removed section in English Units edition "Determination of Boiler Capacity" that wasn't removed in 2009 edition by mistake).
Anyway, this was already present long ago - earlier than 1988 at least.

Wrote

Anyway, this was already present long ago - earlier than 1988 at least.

I agree; however, I will gladly show you the addendums to my version. A chunk of the book is "red".

I use version 1982 ( twenty first printing ) , and the version in Spanish,
in the international system of units , and the English system of units, printed by Mc . Graw Hill
in 2001 of the 1985 version of Crane.

Best Regards

Carlos

Wrote

I agree; however, I will gladly show you the addendums to my version. A chunk of the book is "red".

I don't understand what does it means...
However, if I can, I'll try to help.

My Crane Manual has a lot of addendums/redlines/fixes. I think it was a bad print. The math behind it, empirical formulas and what not, have been around for decades. So I agree that it hasn't changed in a respectable time frame.

Well, actually I found it method somewhat "home-brew". Seems that they invented their way, and used it for so long without aligning with "established" way.

IMHO, the "Crane Check valve", is not a good exercise. There are so many configuration from manufacturers.
If you design something: get the supplier to suggest the best check valve for your fluid & flow conditions.
In industrial process, check valve is line size full open/full close, just a bit of pressure drop that adds
to other piping accidents in the course. Sizing "Control valve" is a much different story.

Check valve belongs to piping design team
Control valve belongs to the Instrumentation.

How do you categorise yourself ? A Pipng Designer or Instrumentation Designer ?

From what you are saying, your crane looks like full of typos , some corrected in red, just a bloody mess for
the recycle bin. If there is something to size about check valve, the source is
"ISA Handbook of Control Valve sizing".

Wrote

Well, actually I found it method somewhat "home-brew". Seems that they invented their way, and used it for so long without aligning with "established" way.

I like your comment. I say same thing(s) in other words.
Just needed to calculate for the specific valve model:
1. sigular Δp @ min/max flow
2. linear Δp @ min/max flow

Calm down.
Check valves should be "sized" similar instrumentation; however, they are considered piping. As a "rule of thumb", the check valve should be a minimum 1 pipe diameter smaller than the pipe (IP) system, similar to control valves rules of thumb for preliminary sizing. I will be more than happy to share horror stories off line (e.g. 36" check valve swap for 24"...$$$).
BTW, Carlos was using a swing check valve (same as I) which tends to give the worst scenario. Other styles show lower loses.

Wrote

Calm down.
Check valves should be "sized" similar instrumentation; however, they are considered piping.As a "rule of thumb", the check valve should be a minimum 1 pipe diameter smaller than the pipe (IP) system, similar to control valves rules of thumb for preliminary sizing. I will be more than happy to share horror stories off line (e.g. 36" check valve swap for 24"...$$$).
BTW, Carlos was using a swing check valve (same as I) which tends to give the worst scenario.Other styles show lower loses.

There is no rule of thumb ½ size valve vs piping, especially if the piping is short.
And all that depends upon the inlet/outlet pressure across the valve. Some valve style
of line size include the reduced entrance. The process fluid governs, not Crane.
I have not seen Dezurikk plug valve in Pulp & Paper of smaller size than the pipe.
Neither in mining, I have seen pinch valve smaller than the pipe. The all matter
is about a high range of controllability, valve style cost vs installed flanged
reducers or welded reducer(s)

Wrote

I have not seen Dezurikk plug valve in Pulp & Paper of smaller size than the pipe.
Neither in mining ...

Jean,

1. Plug valves are for isolation. I am talking about check valves. Isolation valves are typically line size
   
2. those industries see a LOT of constant speed systems
   
3. still bad piping design

Check valves off of pumps should be the same as the pump discharge flange ... which is typically 1 pipe diameter smaller than the system depending on the industry. Reason is that the velocity coming off the pump discharge is up to 10 ft/s while some systems are designed for 3 ft/s. Not enough "thrust" if using line size. Yes, the fluid/process dictates lots of things as slurries are more abrasive and typically pumped at lower velocities like 3 ft/s

Thanks Elsid,

You seem to know things from books. I know valves and more from 30 years design/consultancy.
Plug valves [Tufline, Dezurik] are either isolation [ON/OFF] or control valves for large
size systems which generally don't depend too much upon controllability and are quite stable.