Most airless spray equipment uses a high pressure paint hose between the airless pump and the airless spray gun, excluding handheld airless paint sprayers which naturally do not use high pressure airless paint hose.
Excluding budget orientated DIY airless spray pump units which are often supplied with 25 feet or 7.5 m of airless paint spray hose the most common length found fitted standard to airless paint sprayers is 50 feet or 15 m in length. The most common internal diameter airless paint spray hose is 1/4 inch or 6 mm ID.
Common internal diameters for airless paint spray hose is 3/16 inch, 1/4 inch, 3/8 inch and a 1/2 inch while common standard airless spray hose lengths would be 25 feet and 50 feet. Keep in mind that airless paint spray hose will stretch under pressure and act as a shock absorber which can help minimise any paint pressure pulsations which might be seen at the airless spray gun in certain situations.
Using too little airless paint spray hose or the wrong type of airless paint spray hose can cause pulsing in the spray pattern. Wire or steel braid airless paint spray hose will not stretch or act as a shock absorber as well as rayon or textile braided airless paint spray hose and coupled with the extra sensitive pressure sensing devices that are now fitted to most electric piston airless spray machines these days, a steel wire braided hose may even cause the pressure sensor to shut the airless machine down before desired static pressure has been achieved.
The most common internal diameter airless paint spray hose used would be the quarter inch ID which is more than enough for most applications. Fitting of the smaller 3/16 of an inch ID hose is desired in manufacturing situations to provide greater flexibility aiding operator comfort when using airless spray tip to paint complex shaped objects.
The greatest restriction in an airless paint spray hose is the swaged fitting at either end but in most airless spray painting applications even a 3/16 inch hose coupling has many times greater flow area than even the largest airless spray tip. In certain instances where extremely long runs of airless paint spray hose is being used by coupling multiple hoses together the cumulation of coupling restrictions may be offset by going to a larger airless paint spray hose internal diameter.
Pressure ratings on airless paint spray hose are generally working pressure or safe working pressure which is a calculated formula from the actual tested hose burst pressure. There is no worldwide standard for calculating or advertising safe working pressure on an airless paint spray hose so the advertised figure could be 25% of the actual burst pressure or a third of the actual burst pressure or even a figure based on some other equation depending on the origin of the airless hose and the geographical region the airless paint spray hose is marketed in.
Smaller internal diameter airless paint spray hoses achieve much higher safe working pressures or static bursts pressures than larger diameter hose using exactly the same construction. Safe working or actual burst pressures of an airless paint spray hose can be increased through the addition of additional reinforcing wire or synthetic textile braids woven over the poly amide internal tube. Airless paint spray hose reinforcing braid is usually encapsulated and protected with a protective polyurethane outer cover.
Typically most airless paint spray hose manufacturers supply standard hose lengths fitted with NPS swivel connectors and spring guards to support the airless paint spray hose from kinking at each coupling.