BS ISO 13265:2010 pdf free download Thermoplastics piping systems for non-pressure underground drainage and sewerage — Joints for buried non- pressure applications — Test method for the long-term sealing performance of joints with elastomeric seals by estimating the sealing pressure
5 Apparatus
5.1Source of nitrogen, with a purity of at least 99,8 % or, alternatively, cleaned air (oil-free), both capableof supplying a flow of up to 200 ml/min and at a pressure of at least 10 bar.
5.2Regulator/pressure controller,capable of regulating a stable pressure and flow increase up to120 ml/min.
5.3 Pressure gauge, for measuring the pressure in the main line and capable of checking conformity to 7.2(class 0,6 or better, as specified in EN 837-1).
5.4Connecting tube, with an inside diameter of at least 4 mm.5.5PTFE tube, conforming to the following:
a)capable of sustaining at least 10 bar pressure;
b)the total thickness of the flattened PTFE tube shall be between 0,16 mm and 0,24 mm, measured in the
middle of the sample and carried out in two positions perpendicular to each other;
c)the total width of the flattened tube shall be between 6 mm and 10 mm.
NOTE The PTFE tube used for this test is a blown-up tube,normally applied as a shrinkage tube. The originaldiameter and wall thickness after shrinkage are normally specified. Blown-up dimensions are normally not specified.
The given tolerances should be seen as a guide for the supplier.
Care should be taken that the wall thickness and the diameter of the tube as received are verified.
5.6 Flow meter, with a capacity of 200 ml/min and a tolerance of 15 ml/min.
5.7Means for storing test assembly, capable of fixing and storing the test assembly in such a way thatno additional movements in the joint can occur. lt shall be capable of fixing the PTFE tubes in such a way that,when connecting or disconnecting to the pressure gauge and flow meter, no movement of the PTFE tube inthe sealing area can occur.
5.8Lubricant, an aerosol of silicon(polydimethylsiloxane) with gas propellant(propane/butane).
6 Test pieces
6.1General
Each test piece shall consist of a complete joint, together with its elastomeric seal and PTFE tube(s). Unlessotherwise specified in the referring standard, the number of PTFE tubes shall be three, marked as a, b and c,equally spaced around the spigot.
6.2Assembly
Prior to assembly, the test pieces shall be conditioned at the test temperature for at least 24 h.Clean the rubber sealing ring, the socket and the spigot.
Prepare the PTFE tube by pressing it together several times until permanently flattened and place it along thesmooth surface of the spigot or socket.
Lubricate the smooth wall in the joint (spigot or socket), the seal and PTFE tube(s). The lubricant definedin 5.8 shall be used.Use sufficient lubricant to ensure that the PTFE shrinkage tube(s) and seal can beassembled without damage,and the seal can equalize its position within the groove circumference.
Assemble the socket and spigot, including the seal, in accordance with the manufacturer’s instructions and thefollowing requirements.
a) The joint shall be assembled in such a way that the PTFE tubes are mounted between the spigot or
socket and the seal (see Figure 1); precautions shall be taken to avoid squeezing the PTFE tube outsidethe sealing area.
b)lt is permitted to mill a grove, insert thin plastics strips along the tube, drill holes in the spigot or socket or
any other method that gives room for’sufficient flow through the tube outside the sealing area.Themethod selected shall not significantly influence the creep behaviour of the joint in the sealing housingarea.
c)Make sure that the PTFE tube can move freely in the axial direction and that the flattened section of thePTFE tube is located under the sealing ring, and not distorted, when the joint is made.
6.3Leaktightness of the test system
Make sure the pressurized side of the test equipment is leaktight after installation. ldentify any leakage bysoap solution. If necessary, reassemble the leaking joints.Avoid flow through the sealing zone during thisanoratinn