19.1 Chemical compatibility overview
Ensuring chemical compatibility is a key requirement in determining if the pumped fluid and the chemical
environment the pump is operating in, is within scope of the
intended use
of the product.
Chemical compatibility analysis is based on which materials of construction would be in contact (wetted) with the
fluid or environment, as represented by the 3 scenarios in this table
Scenario 1
Scenario 2
Scenario 3
Fluid Path (wetted by the
pumped fluid in normal use)
Potential of being wetted due to
environment or spillage
Potential of being wetted due to
operating the pumphead to the
point of failure
These materials of construction
will come into contact with the
process fluid during intended
use
These materials of construction could
become wetted due to a chemical spillage,
cleaning or the environment the pump is
operating in
These materials of construction
will come into contact if the
pumphead is operated to the
point of failure
Pumphead: Fluid path
l
Internal tube or
element
l
Pumphead ports
l
Pumphead port seals
l
Process: Fluid path
l
Pumphead hydraulic
connections
l
Interface tubing
Drive:
l
Casework
l
Casework seals
l
Keypad
l
Driveshaft
l
Driveshaft seals
Pumphead:
l
Casework
l
Pumphead ports
l
Connection collars
Pumphead:
l
Internal parts
Pumphead to drive interface area
:
l
Drive shaft
l
Drive shaft seals
l
Drive casework
l
Drive casework seals
NOTE55
The pumphead is not sealed to the drive. The air of the environment in which the pump is
operating can circulate between the pumphead and the drive (pumphead to drive interface area).
NOTE56
If the pumphead is operated to the point of failure and the pumphead internals are not chemically
compatible with the pumped fluid, then the materials of construction in the pumphead to drive
interface area will be exposed to the pumped fluid.
19 CHEMICAL COMPATIBILITY
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