28.4 Behaviour of Masterflex hoses under pressure and under vacuum
General
All catalogue details are the result of internal tests and experimentation in accordance with international standardisation recommendations and relate to a medium and environmental temperature of + 20°C. Different temperatures may alter the pressure and vacuum details. Depending on the design, a change in the length of individual hose types is possible caused by the effects of the pressure, vacuum, temperature of the medium and environment. This change in length must be taken into account by the user during operation. (Also refer to "How to position hoses correctly")
Operating pressure
The operating pressure is the maximum permitted overpressure of a hose, at which this can be used.
Test pressure
The test pressure is up to 50% above the operating pressure, depending on the hose design. The hose may not have any leaks and permanent deformations at test pressure.
Bursting pressure
The pressure at which the hose is destroyed is described as the bursting pressure. The bursting pressure is used to determine the operating pressure taking into account the normal, general safety factors. The bursting pressure is determined in accordance with EN ISO 7751.
Vacuum
The vacuum details for Masterflex hoses are determined in accordance with DIN 20 024, point 15.
Testing the vacuum resistance:
During the vacuum tests the hoses are placed in a 90° arc in compliance with the minimum bend radius and vacuum is applied until they show signs of indentations or collapse. The permitted vacuum in continuous operation is determined by taking into account a general, standard safety factor.