[Spruce]

Shurflo recommend that the motor should be mounted with pump motor at the top and the pump's water connections at the bottom. The reason they say is that should there be a water leak it won't compromise the electrics. This means the redundant pressure switch would be at the bottom.
In the early days Peter Fogwill mounted the Shurflo pump the other way round.

Did you get strainers with the pumps Tosh?

[Tom White]

Did you get strainers with the pumps Tosh?

I forgot to order any, but Cleaning Warehouse (not WCW) kindly dropped one in, which is why I haven't made a big fuss and whine about the delay in delivery to me! 

I guess I just need the one, which I'll position exiting the tank just prior to splitting the hose to go to separate pumps.

Thanks though, I like these questions; it keeps me doing things right.