How to Choose a Spray Nozzle Model

There are many types of nozzles, and the users need to choose a nozzle that meets their requirements to achieve the ideal spray effect. For example, fan-shaped nozzles are suitable for cleaning, degreasing, cooling, etc., and cone-shaped nozzles are suitable for rinsing, surface coating, scaling, humidification, dust removal, etc. Nozzles that require a certain impact should use small-angle nozzles, and use solid stream nozzle is the best.

The following points to be noted when choosing a nozzle:

1. Nozzle Type

According to the spray effect, droplet size, and application, the users can choose the suitable nozzle type.

2. Nozzle Pressure and Flow Rate

After confirming the pressure and flow rate of the nozzles, the connection size of the nozzle can be determined.

3. Nozzle Connection Method

Connection methods can be divided into internal threads, external threads, flange connections, welding, and bonding. (Imperial, American, National standard)

4. Nozzle Material

It is selected according to the temperature, strength, acidity, alkali, corrosiveness, and abrasiveness of the working conditions. For example, there has brass, 303SS, 304SS 316SS, aluminum, cast iron and polypropylene, etc.

Example analysis of nozzle selection:

The nozzles used for degreasing and washing can choose nozzles with high-impact force. Taking the fan nozzle as an example, the best spray angle is 60°, which can bring ideal impact force. 

Centrifugal nozzles are suitable for phosphating processes that require atomization with fine and uniform droplet size but no need for high-impact force. 

In the case of the cone-shaped nozzle, the optimal distance between the nozzle and the workpiece is 40cm~50cm, which has the best spraying effect of dispersing and atomizing the liquid.

These factors of flow rate, pressure, coverage, material, impact force, spray angle, temperature, application, etc., are correlated and constrained mutually. 

Normally, the higher the pressure is, the larger the flow rate is, and the spray angle is also in direct proportion with the coverage. 

The purpose of any nozzle injection is to maintain continuous contact between the tank and the workpiece, where the flow rate is more important than the pressure. 

The temperature of the liquid does not affect the spray performance of the nozzle, but it affects the viscosity and specific gravity and also affects the material selection. 

The material of the nozzle should also be determined according to the chemical characteristics of the liquid. If the liquid is non-corrosive, it can be cast in bronze or plastic according to the difficulty of processing, and non-metallic materials can be used to prevent corrosion; for sulfuric acid, hydrochloric acid, and other strong corrosion liquids, you can use nylon material. The nozzle material for a phosphating tank is generally made of acid-resistant stainless steel, and the nozzle to prevent rust can also be directly made of stainless steel or nylon.