Orifice Plate straight lengths requirements 1

[MJC42]

Hi
The upstream straight length requirements are covered in ISO 5167 but what about downstream straight length requirements if any. I have a situation were the 16" pipe work has to be increased to 18" in order to allow a beta ratio less than 0.7 ( even with a max DP of 500mbar ), but should it also be increased to 18" downstream and for how long? The downstream pipe work is going into a compressor. Thanks in advance for any advice.

 

[hacksaw]

you might try an alternative meter (e.g. insert d/p) if there is no other reason to increase pipe size.

 

[m777182]

ISO 5167-1:1995 page 9 last column covers downstream straight lengths for different betas and armatures.It is claimed that ISO does not provide any information about a set up that is not within the prescribed limits given there,so I would increase a downstream pipe as well.
m777182