nobody knows a suitable composite for the above application as to many parameters are missing, like:-
Expected production numbers?
Temperature of the water?
ph of the water?
Physical loads applied to the parts?
Potential heat transfer from the motor to the pump?
Possibilities of water also containing abrasives or debris?
Load on the parts?
Approximate design details of the pump?
Is light weight important?
What life expectancy is there?
Will it be exposed to UV light?
How much does cost limit the choices for other properties?
How tight a tolerance is required for he parts?
Does the tolerance need to be held over an extended time period?
Will it constantly be wet or will it be used occasionally then left in a dry environment for an extended period of time?
If the numbers are high enough for injection moulding to be viable and the ph is not to low, I would think probably GF nylon due to overall strength and toughness. It is used for virtually all automotive radiator header tanks, is used for all plastic inlet manifolds and valve covers and timing chain tensioners. It is also used for some automotive water pumps and some top end power tool housings and pumps used in underground mining.
If ph is low, GF PET. It is more rigid than nylon and better at low ph, but poor to hot water.
If it is more cost sensitive but can be bulkier or have lower life or is lightly loaded GF PP might be OK.
If it is low volume, probably fibre glass reinforced polyester is OK.
There are a great many assumptions in the above answer. All of them may very well be wrong and if so, I just wasted my time composing it and you wasted your time reading it.
The OP just plain did not ask an answerable question. My nonsense first answer I thought was an obvious indicator to that which had just enough sting to maybe be remembered and therefore motivate him to do better next time he attempts to draft a question.
Regards
Pat
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