Understanding Sprays Series No 8. Specifying your spray nozzles

Product

This is the final article in our nozzle knowledge series. In this article, we look at what information a nozzle supplier will request from you to specify the correct nozzles for your application. Having this information to hand will ensure an efficient specification and delivery process and will enable your supplier to identify any issues early in the process.Prefer to watch a video version, please click here? Or, if you would like to download a pdf version, click here.

APPLICATION

Firstly, the most important piece of information we require is the application. Here at SNP, we have decades of experience dealing with various spray applications. If the application is specified at the start, our knowledgeable experts can offer immediate and useful advice from past experiences dealing with similar applications.

FLUID SUPPLY

Our team need to know:

  • The maximum pressure that the pump can maintain.
  • The flow rate that the pump can maintain.
  • The pump curve (the relationship between pressure and flow rate)
  • The pipe factors between the pump and the nozzle (the likely frictional and gravitational pressure losses)
  • What the nozzle can see (the range of pressures and flow rates)
  • The flow rate (variations and tolerances – applications such as coating will have a precise flow rate. But for other application such as dust control, the flow rate will be less refined)

TARGETING

Our top targeting questions are:

• How are we going to accurately direct the spray? Will there be any leeway there?
• Where does the fluid need to go?
• Do you need an even or uneven distribution of fluid?
If you provide the answers to those questions, this will equip your supplier with all the correct information to correctly position the nozzle and ensure the spray hits the target.

AIR

When contacting us, we need to know if air is available. The top questions regarding air would be:

• Is it possible to use air in this application as this widens the options available in terms of nozzle selection?
• Are air atomisers an option?
• Is the air on site?
• If not, is it possible to get air on site?

ENVIRONMENTAL CONDITIONS

Our team need to know:

• The temperature at which the liquid is going to be sprayed
• What the nozzle is going to be spraying into, (this will significantly affect the material selection)
• If it is going into a gas flow, what is the gas flow and will it be moving? Is there going to be any variation?
• If conditions are windy as this can affect the direction of the spray
• Corrosive factors – is the environment likely to be corrosive?

FLUID PROPERTIES

All data sheets are calibrated for water and if it is just water being sprayed, this isn’t an issue.

But if a different liquid is being sprayed with a different viscosity and specific gravity and surface tension, we will need to know what the fluid properties are to ensure the appropriate adjustments are made.

In a previous article, some equations were featured to show how spray factors such as flow rate and drop size are calculated.

The other fluid property that is important to understand is particulate content. How well filtered is the fluid going to be? If it's pure and very well filtered water, this gives us lots of options. But if there are going to be contaminants that can clog up the nozzle, our options become limited because we'll need to look at clog resistant nozzles.

CONCLUSION

If you can provide a nozzle supplier with as much of that information as possible, they can easily specify the correct nozzle. In some applications, we realise that not all of this will be precisely defined but a good supplier will be able to guide you through the process.

For more technical nozzle and spray information, head to the resources page of our website here.

About SNP

SNP aims to take the hassle out of procuring small engineering components - spray nozzles and spray systems - with expert, friendly, fast advice and product specification.

SNP supplies spray nozzle solutions to industries worldwide, including the largest engineering, food processing, chemical and petrochemical companies, as well as a vast array of small and medium sized enterprises (SMEs). The company’s product range includes tank washing nozzles, hydraulic nozzles, air atomising nozzles, custom piping assemblies and spray accessories as well as disinfecting and washdown systems.

SNP is as skilled in advising design engineers at the beginning of projects as it is recommending and supplying replacement products that may be needed in a hurry. The company can also provide innovative custom solutions, including using non-standard materials. SNP holds ISO 9001 certification. SNP is an exclusive distributor for US spray nozzle manufacturer BETE, for pre-treatment specialist Uni-Spray, specialist paper industry nozzle manufacturer ML Gatewood and tank cleaning systems manufacturer Dasic. In addition, SNP supplies specialist spraying equipment from Guarany. Orders are handled quickly and efficiently from SNP’s own dedicated fulfilment facilities in the Midlands.

01273 400092 | info@spray-nozzle.co.uk | www.spray-nozzle.co.uk