An introductory guide to hose fittings, couplersand adapters for pressure washer（2）

Let’s continue last article:

Let’s look at the advantage and diavantage of each:

Plastic fittings

Plastic fittings will be used only for lightweight electric pressure washers.

• Advantage – Cheap. Light.
• Disadvantage  – Prone to cracking and damage

Brass fittings

Brass is the most commonly used fittings material for pressure washers by far  . It is a copper-zinc alloy, low melting point, easy to cast and machining.

Stainless Steel fittings

Chromium is added to stainless steel to prevent it from rusting.

• Advantage – – Best for corrosion resistance. Chemical resistant. High strength.
• Disadvantage– Expensive.

Rubber O-rings

Use o-rings in female fittings to prevent leaks. Quick-connect sockets are suitable for female sockets and the o-ring is the perfect size to prevent leakage.

Sizes 

When purchasing fittings, the main confusion is the size you need to get.

• Did you measure the inside diameter or the outside diameter?
• Do you include threads in your measurements?
• How precise do you need to be?

Even using numbers, caliper, is difficult. Some accessories are 3/8″ , some are 22 mm, some are 14 mm bore diameter (some need 15 mm) , sometimes you will find accessories in excess of British pipe thread standards, some labels QC F or QC M confusion.

Let’s take a closer look at what all sizes mean for fittings.

How to Measure Connections and Fittings

Calipers will be required to measure the parts you need correctly. A measuring belt will work, but it won’t be as good as we’re talking about a 1 mm difference.

Here are the best calipers:

Here are some other things to know about  power washer adapters:

Female(F)  vs. Male (M) connections

The male side has a pin or plug inserted in the female socket or hole. The female fittings receives and maintains the male fittings in place.

NPT vs. BPT/BSP pipe thread standards

• NPT = National Pipe Thread. U.S. technical standard for screw threads.
• BSP = British Standard Pipe. British technical standard for screw threads.

Quick Connect Plug and Socket Sizes

All the quick couplings we’ve seen have been 3/8″ QC. You don’t need to get the calipers out for the quick connects.