Home / Resources & Training / Tips of the Trade / Airless Hose Sizing is Critical for Effective Spray Coating Application Airless Hose Sizing is Critical for Effective Spray Coating Application Posted in Painting & Coating, Safety Tip: #72 Select the Correct Airless Host to Prevent Burst Failures and Increase Productivity Often the selection of an airless hose is based on cost or ease of use. By ensuring you select the correct airless hose you not only safeguard against dangerous burst failures but you can also increase productivity. Spray with the correct pressure rated hose The most flexible hose may not always be the safest to use. The pressure rating of the hose should always be higher than the maximum output of the pump. There is a severe risk of personal injury when using a spray hose with a pressure rating which is less than the pump output pressure. If flexibility is a major issue, use a smaller ID whip hose between the gun and the main hose with the correct pressure rating. This will cause less pressure drop than running the entire length in a smaller ID hose. Spray with as large as is practical ID hose When you increase the size of your paint hose, you decrease pressure loss and improve flow. Reduced pressure loss helps the pump to work more efficiently. Flow improvements that come from increasing hose size include not only higher volume but smoother flow as well. Smoother flow reduces pulsation which in turn provides a more even spray pattern. Check the hose pressure rating on your airless hose All airless hose is manufactured with a burst point safety factor to ensure that in an emergency the hose will cope with being over pressurized. Hose has 4:1 safety factor. i.e. a 7250 psi hose will take up to 29,000 psi. Many cheap hoses have a lower safety factor. Construction of a spray coating hose The construction of an airless hose can vary slightly according to the type of hose. The illustration above is for a high pressure hose. A lower pressure hose may have less reinforcement to provide greater flexibility. Hose types Spray hoses are available in various types, sizes and lengths including special Teflon core liner hose. The colour of the hose indicates the recommended output psi. Spray coating whip hose Whip hoses are lightweight, flexible hoses which makes spray gun movement easier for the operator. Safety spring guards are fitted to whip hose ends. How to Select the Correct Airless Hose Part Number Hose ID Hose Braid Type Colour Max Pressure Description SPH063350 1/4" Fabric Blue 3,300psi Highly flexible. A gener purpose hose for use on pumps electronic controls. SPH066050 1/4" Wire Purple 5,600psi Common hose for spray coating application due to its good all round performance. SPH067250 1/4" Heavy duty double wire Red 7,250psi Used for high build coatings and pump ratio upto 80:1 SPH103350 3/8" Fabric Blue 3,300psi Larger bore size for higher flow and higher viscositie coatings. SPH104550 3/8" Wire Black 4,500psi Used for high build coatings and pump ratio upto 45:1 SPH107250 3/8" Heavy duty double wire Red 7,250psi Common hose used for high ratio pumps upto 80:1 SPH135650 1/2" Wire Green 5,600psi Used for Ultra-high build and high viscosity coatings. Also used for longer hose lenghts to reduce pressure loss. SPH137250 1/2" Heavy duty double wire Red 7,250psi Ultra high viscosity coatings and pups up to 80:1 The part numbers listed above are for 50' (15 metre) lengths. Other sizes and pressure ratings are also available. Please contact BlastOne for other available options. Tip: #72 Share this Download pdf Related Links > Is Your Airless Hose Blocked or Restricted? > How to Select the Correct Spray Paint Pump for Your Job > Is Your Spray Tip Worn?