Downstreaming
Downstreaming is drawing cleaning solution into a pressure washer's water after the pump, through an injector, so it comes out of the wand at low pressure.
- downstream injection
- downstream injector
- chemical injector
A downstream injector sits on the high-pressure line and pulls chemical in when a low-pressure (soap) nozzle is used. It is the simplest way to soft wash with a pressure washer, and the chemical never passes through the pump.
The injector dilutes the chemical heavily, so the strength at the surface is a fraction of what is in the bucket. That suits house washes, but it can make stronger mixes hard to reach, which is one reason many companies use a separate low-pressure pump for roofs. Check your injector's draw rate to know the real strength you are applying.
Formula
strength at the nozzle ≈ bucket strength × injector draw ratio
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Related
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