What is the Difference Between a “Wet Boom” and a “Dry Boom”?

You are probably here because you keep hearing people refer to a “wet” boom or a “dry” boom on a sprayer. We are spraying liquid so all booms are “wet”, so what is the deal?

The difference between a Wet and Dry spray boom is how the liquid is supplied to each nozzle body. On a wet sprayer boom, the liquid travels through a rigid pipe and each nozzle body is attached directly to the boom. So the boom is “wet”. A dry spray boom uses hoses to supply liquid to each nozzle body and the nozzle bodies clamp onto a boom pipe or tube that does not have liquid flowing through it, so it is “dry”.

Examples of a “Wet” and “Dry” Sprayer Boom

A “Wet” boom is defined as a boom that is made of a rigid pipe with nozzle bodies attached directly to it. The pipe carries the product to the nozzle bodies. The image below shows a wet boom.

Example of a “wet” spray boom.

A “Dry” boom has nozzle bodies mounted to the boom frame with clamps and the product is supplied to the nozzle bodies via hoses. The image below shows a dry boom nozzle body.

Example of a “dry” spray boom.

What is a Nozzle Body?

The nozzle body is the part of a sprayer boom that the nozzle connects to. It will be held in place via a clamp and supplied by either the boom hoses (dry boom) or the wet boom pipe. There are many types of nozzle bodies. The simplest kind is basically a hose bar elbow or tee with 11/16 nozzle body thread, commonly referred to as TeeJet thread. More complicated nozzle bodies have check valves to stop the nozzle from dripping, or multiple nozzle turrets to allow for quickly changing between different nozzle types.

There are many different types of nozzle bodies. For more information, this article explains nozzle bodies in much more detail.

From left to right: Dry boom nozzle body with check valve, simple dry boom nozzle bodies, multiple nozzle body for wet boom.

What Is the Advantages and Disadvantages of a Wet or Dry Sprayer Boom?

Wet Boom Advantages

  • Easier to replace broken nozzle bodies. Just undo the clamp on the nozzle body and it comes right off.
  • Easier to clean/flush out than dry booms.
  • Small wet booms can be self-supporting, and therfore much simpler than a dry boom. You can see the example below is intended for adding to a small spot sprayer. It is much simpler than mounting nozzle bodies and running hoses to each one. (You can click here check the price and see more details at domyown.com.)
Simple poly wet boom for backpack or spot sprayers.

Wet Boom Disadvantages

  • Can be more expensive than dry booms.
  • If the boom pipe is PVC or poly it can break if it is hit by a fence, tree, etc.
  • Must drill holes in the boom if you want to change the spacing of the nozzles.

Dry Boom Advantages

  • No drilling or tapping pipe if you want to make changes to the nozzle spacing.

Dry Boom Disadvantages

  • Hard to change nozzle bodies becasue you need to pull brittle old hoses off of the hose barb nozzle bodies.
  • Boom hose crakcs, sags, wears out over time.
  • Sagging hose between nozzle bodies can trap residue and make boom harder to flush out.

Wet Vs. Dry Boom, Which is Best for You?

Ultimately the type of spraying and your personal preference will decide what works best in your scenario. Wet and Dry booms can be used for just about any size or type of sprayer. Ranging from small ATV booms to large row crop sprayers.

Sprayer Guru

I have more than a decade of experience using, building, studying, and testing sprayers in several applications. With the knowledge I have gained I want to provide straight forward and detailed answers for DIY homeowners, farmers, and commercial turf and tree care pros.

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