Spray nozzle holders

Our spray nozzles are used in a wide variety of applications. Attaching the spray nozzles to the correct point on the fluid supply systems requires the use of nozzle holders. There are several types of holders available and this short article explores the main types and lists the advantages and limitations of each.

Direct thread to pipe

For thick-walled pipes it is sometimes possible to directly tap a female thread into the pipe wall itself. A male threaded nozzle can then be directly threaded into the pipe. Obviously, this means the nozzle cannot be adjusted or removed easily and it relies on having thick enough pipework to maintain a suitable thread. It is only recommended for low pressures systems and when a leak or dripping will not cause serious issues.

Welded threaded boss

When the nozzle is required to be in a completely non-adjustable position then a welded boss onto the exiting pipe work will provide a point to thread the nozzles in. Most nozzles use tapered threads and so are not designed to be removed regularly and once the thread point is welded on it is obviously not going to be changed. So, nozzles threaded into this connector can be changed for maintenance, but it is only recommended to do so infrequently. Whilst this holder type offers little flexibility it offers unparalleled pressure ratings, potentially up to several hundred bar, and has very little chance of leaking or dripping.

Push fit tees

Threaded push fit connectors can come in plastic or metal. The two pipe sides of the tee will push directly onto the pipework and present a thread perpendicular to the pipework. The orientation of the nozzle can potentially be adjusted by 360 degrees but only in one direction. They also give great flexibility in where the nozzle can be positioned along the pipe length as the pipe between the nozzles can be cut to any length.

• Push fit tees can be used in flexible or ridged pipes of various diameters.
• For flexible pipes (hose) they can handle up to about 6 bar fluid pressure
• Most standard push fit connectors for rigid pipes in plastic will work up to about 10 bar pressure
• Metal push fit connectors are commonly available for use in systems up to about 20 bar
• Specialist high pressure push fit connectors are also available for systems of 100 bar fluid pressure or more.

Clamp holders

With these nozzle holders a clamp or eyelet is placed around the supply pipe work with a spigot that inserts into the pipe via a pre-drilled hole and a O-ring to form a seal. The clamp is then tightened to fix it in place. The nozzle is then threaded into the clamp holder.

This type of assembly removes the need to thread into the pipework or welds a threaded boss onto the pipe. In effect they turn a drilled hole into a thread connector for the nozzle. When lots of nozzles need to be attached to lengths of pipework at different orientations this can greatly reduce installation cost as all that needs to be done is to drill the appropriately sized hole in the correct position.

• For maintenance and cleaning the clamp assembly can be removed. Often this can be done without tools, so the removal of nozzles becomes a lot quicker and easier.
• Clamp holders are available for use on plastic and metal ridged pipework and some semi flexible plastic pipework.
• They will operate up to about 10 bar depending on the model and clamp type.

Swivel joint holders

Swivel joint holders are either threaded directly into a thread point on the pipework or form part of a clamp holder assembly. So, they are not a different type of nozzle holder per se but they are worth mentioning as they offer a great degree of versatility.

The nozzle will typically be threaded into a metal or plastic ball socket that allows the nozzle orientation to be adjusted by 360 degrees (which is important for flat fan nozzles) and then the direction of the nozzle can be adjusted by 45 degrees in two dimensions. Once the nozzle is orientated and align it can be fixed in place by tightening a retaining clamp. This allows for nozzles to be easily adjusted to ensure sprays remain exactly on target.

Dovetail holders

When exact orientation is important and when it is anticipated that the nozzle will need to be replaced often then dovetail nozzle holders might be a good option. Typically, the base unit of the holder will be threaded into the pipework or boss, the nozzle itself will then lock into this base unit. The base will always remain in place and just the dovetail nozzle is removed for maintenance.

Conclusions

There are many ways to attach spray nozzles to fluid delivery pipework. Whilst this might not be the most fascinating of topics, some knowledge of the different methods can have a significant impact on design of spray systems. A little knowledge can help save time and money in the future.