Technical Specifications - Compressed Air System Connections

NOTE: This specification refers primarily, but not exclusively, to our compressed air range of fittings prefixed PM and MM. Other fittings, valves, tubing and auxiliary products have their own technical specification.

Product selection and installation

John Guest fittings and associated products are specially designed and manufactured by John Guest in accordance with the technical specifications set forth in the John Guest product catalogs. All John Guest fittings and associated products must be selected, installed, used and maintained in accordance with these technical specifications. It is the responsibility of the customer/user to ensure that John Guest fittings and associated products are suitable for their intended applications, are properly installed and maintained and are used in accordance with the technical specifications. It is also the responsibility of the customer/user to provide their own customers with all relevant technical information on the John Guest products they supply. If you have any questions about our technical specifications, please contact us.

For use with chemicals or other potentially aggressive liquids, please refer to our customer service.

Super Speedfit fittings and related products are not recommended for use with explosive gases, petroleum spirits and other fuels or for use in central heating systems.

Maintenance and replacement intervals

John Guest products are generally low maintenance, but we recommend at least a routine visual inspection. The frequency of visual inspection will depend on the severity of the application and the risk of failure. If, after visual inspection, John Guest products appear damaged, cracked, charred, discoloured, heat distorted or corroded, they should be replaced. Any product that leaks or appears to be leaking should be replaced.

Product life is affected by the severity of the application, the hostility of the working environment and contact with aggressive chemicals or liquids. It is therefore important that specific replacement intervals are considered by specifiers/users/customers based on previous service life or where failure could result in unacceptable downtime, damage or risk of injury.

Installation and testing of the system

Fittings and tubing must be kept clean and intact before use.

All pipe and fitting installations must be pressure tested after installation to ensure system integrity before being released to the end user. See also "How to make a connection".

Working temperature range

Minimum operating temperature = -20 ° C

Maximum operating temperature = + 70 ° C

The above is for use with air. For temperatures below 0° C, please consult our customer service.

Operating pressure

The John Guest compressed air system is suitable for the following temperatures and pressures.

The above ratings are for air. For use with other media or tubing or at other temperatures and pressures, please consult our customer service.

Types of pipes

John Guest fittings are intended for use with John Guest nylon pipe, but are also suitable for use with a wide range of plastic and flexible metal pipe including UPVC, ABS, polyethylene, nylon, mild steel and copper within the tolerances shown below. Flexible plastic pipe, such as nylon, should have a minimum wall thickness of 1.5mm. The hose should have a good quality surface and be free of damage.

Pipe tolerances

These John Guest fittings are designed for pipes with the following outside diameter tolerances

Clamp covers

Are available as additional security against tube removal or to provide a simple means of colour coding. The cover is available in a range of six colours.

Maximum torque values

The following maximum torque values must be applied.

It is recommended that all installations be checked before use to determine that a seal has been made.

Do not overtighten the plastic fittings as this may result in excessive stress and possible failure. Recommended torque values are listed above and should be followed. John Guest recommends that OEM customers consider replacing the threaded "ports" with the modern method of using John Guest cartridge systems.

Cleaning and disinfection of acetal fittings

Our advice to customers is to use cleaners and disinfectants that are higher than ph4 and low in hypochlorite. Acetal fittings and parts that are cleaned and/or disinfected should be rinsed immediately with copious amounts of clean tap water to remove all traces of cleaning agents.

Details of products made from acetal are shown in our catalogues, but generally John Guest products incorporating acetal are designated by the part number prefix PI, PM, CI, CM and RM. Polypropylene fittings offer greater resistance to aggressive chemicals than acetal fittings. Polypropylene does not have the same mechanical properties as acetal and John Guest Polypropylene fittings are generally referred to by the reference prefix PP and PPM.

Our material suppliers recommend ECOLAB Oasis 133 as a suitable cleaner for acetal products manufactured by John Guest.

Facilities - Our recommendations

The pressure rating and installation guidelines of the respective pipe must also be taken into account when designing a compressed air system.

The pipe shall be supported at least 800 mm to prevent excessive load being applied to the fitting. These supports shall not be closer than 25 mm to the end of the fitting.

John Guest fittings and hoses should only be connected after the air tank and not directly to a compressor.

We recommend installing collar covers when piping is hidden inside walls and ceilings.

It is recommended that all pipe and fitting installations be pressure tested after installation and before handing over to the end user.

guarantee

Although we give a warranty against defects in workmanship or materials, it is the responsibility of the specifier to ensure that the fittings and associated products are suitable for their application. Installation must be carried out correctly in accordance with our recommendations, in accordance with recognised codes of practice and relevant national standards, and be properly maintained. Please refer to our terms and conditions of sale.

The company has a policy of continuous research and development and reserves the right to change the specification and design of all products without notice. John Guest reserves the right to alter the colour and shape of products. Photographs are for illustration purposes only.

Flow rates for aluminium and nylon pipes

NB The figures given for the main air flows in the ring may be doubled as the flow is bi-directional