[Chris jones]

Need advice.
Brought all relative parts pipes regulator etc.
Im just wondering why there are 4 ports.
The way im going to install it is just use the one side a simple in and out and blank off other side.
Thank you for any advice

[Mike Halliday]

Show us a picture

But  most high pressure pumps have 2 inlets 2 outlets either side

[John Kelly]

You can have one inlet but you must use the two outlets. One of them to a bypass. If not you'll have massive pressure build up when not spraying and will damage pump.