how to add chemical injecton to the goliath

[jazonfire]

getting the goliath 500 psi unit how do i add a rinse to my exctraction

[Donald]

chemical injection with the Goliath 500 psi carpet cleaning machine

You have to have 3 items:
Up stream injector

http://www.steam-brite.com/pressure-supply-high-pressure-stream-soap-injector-85400003-p-10843.html

and
Pressure reduction valve

http://www.steam-brite.com/pressure-reducer-valve-male-garden-hose-regulator-87111640-p-10422.html

Larger spray jets on your wand.
Example on dual jet wands, the 01 jets need to be replaced with 02 jets or 03 jets depending on the incoming building pressure.

http://www.steam-brite.com/teejet-brass-11003-p-4956.html

Even though the Goliath is normally a pressure feed system, you can just drop the 6 ft sink connection hose directly into a bucket, trashcan, bathtub,... with your water and rinse chemical.

In either case, up stream injection, or suction feeding the pump causes the pressure to be reduced on the triggered rinsing. In other words, if the gauge was set at 450 psi then you squeeze the trigger on the wand, you will experience some pressure drop off. How much will depend on number of jets and size of jets you are using. This is true with all suction feed machines.