Requirement of dead leg in purified water system as per latest version of USP and for diffrent guidlines(USFDA,WHO,MHRA etc.) and other standards ( ASME - BPE 2007 ) which is to be prefered.
Consider ASME-BPE 2007
you can refer a book by name : PHARMACEUTICAL FACILITIES PLUMBING SYSTEMS
by: Michael Frankel
Published by ASPE:American society of Plumbing Engineers.
Dear Sir,
As WHO mentioned the dead leg as 1.5 D and ASME - BPE-2007 says it is 3D. Which we should refer ? Kindly comment.
Follow WHO guideline.
Dead leg in the water system is something we cannot totally avoid, but we can minimize it. the shorter dead leg will be better to prevent the microbial growth in your system. please refer to the ASME BPE Latest edition 2009, they mention the requirement dead leg should < 2D.
I know deadlegs are must be <1.5D (WHO).But if it is more bigger (ex.<6D) Do we have to do?
Do we have to change?Also specifications can change again and changing deadlegs and Ra are difficult.In this case,what do we do and which specification is more true (WHO,ASME,EP,USP)?
Also as I am new in this work, can you share me information about maintenance the system?Is there cleaning procedure yearly for purified system or othet maintenances
Regular cleaning of the Purified water systems is required. The sanitization procedures are regular and this keeps the system in good health without build up of microbial mass or biofilms.
There will be procedures for cleaning and sanitization of purified water loops and they are also passivated as per time schedules.
Calibration,Prevention of leaks,Changing of gaskets, Valves, Filters etc are in annual maintenance procedures which should be well planned and documented.
Such documents should be available in maintenance and shall be written by QA and Engg teams.
To have an Idea please refer Validation templates–Water system.