GB/T 18241.1-2014Rubber lining-Part 1: Anticorrosion lining for equipment (English PDF)

3.1 Heat-vulcanized rubber lining

heat-vulcanized rubber lining refers to an un-vulcanized rubber sheet which is pasted on the lining equipment by adhesive to form a vulcanized lining

3.2 Pre-vulcanized rubber lining

pre-vulcanized rubber lining refers to a pre-heated vulcanized rubber sheet which is pasted on the lining equipment by adhesive to form a lining

3.3 Self-curing rubber lining

self-curing rubber lining refers to an un-vulcanized rubber sheet which is pasted on the lining equipment by adhesive to complete the vulcanization process under natural conditions

4.1 Classification

4.1.1 Lining, according to the need for heating vulcanization, is classified into two categories.

a) heat-vulcanized rubber lining, expressed as J;

b) non-heat-vulcanized rubber lining.

1) pre-vulcanized rubber lining, expressed as Y;

2) self-curing rubber lining, expressed as Z.

4.1.2 The lining is classified into two categories according to the hardness after vulcanization.

a) hard adhesive, expressed as Y;

b) soft adhesive, expressed as R.

4.1.3 The classification of the lining is shown in Table 1.

Classification Heat-vulcanized hard adhesive Heat-vulcanized soft adhesive Pre-vulcanized soft adhesive Self-curing soft adhesive All technical requirements listed in this section are type inspection items.

Usually, the type inspection should be conducted in one of the following cases.

d) when production is resumed after the production has been discontinued for more than six months;

e) when the results of the exit-factory inspection and the previous type inspection are quite different;

7.3 Determination rules

7.3.1 If one item of specification and surface quality fails, this roll shall be determined as unqualified.

7.3.2 If one item of physical properties listed in Table 3 and resistance to chemical media properties listed in Table 4 fails to meet requirements, it shall take double test specimens from the same batch of products for the re-inspection of this item. If the results of the re-inspection are still unqualified, this batch of products shall be unqualified.

7.3.3 Lining rubber sheet integrity detection, if one part of the selected roll fails, this roll shall be determined as unqualified, it shall take double rolls from the same batch of products for the re-inspection of this item. If the results of the re-inspection are still unqualified, it shall detect each roll. Determine whether each roll is qualified based on the test results.

7.3.4 If specifications, surface quality, physical properties, resistance to chemical media properties and lining integrity are all qualified, this batch of products shall be determined as qualified.

A.1 Principle

It uses the principle of which the air between high frequency voltage breakdown pinhole or crack generates electric spark so as to detect the integrity of the anti-corrosion rubber lining (if there are pinholes, cracks and other defects).

A.2 Applicable scope

It is applicable to non-conductive anti-corrosion rubber liner integrity detection. It is not applicable to conductive anti-corrosion rubber lining detection.

A.3 Apparatus

A.3.1 The EDM pinhole detector maximum output voltage should be at least 20000 V; the measured voltage should be stable within ± 10%.

A.3.2 The safety of the EDM detector shall prevent the user from touching the probe without causing danger. A.3.3 The detector should have a defect alarm function.

A.4 Detection steps

A.4.1 Selection of voltage for detection

The detection voltage is typically 3000 V per millimeter thick, or is selected according to the supplier and the purchaser. The total voltage for detection should not exceed 20000 V.

A.4.2 Selection of electrode for detection

In the detection parts of which the lining area is small, seams and complex parts, it shall select qualified straight electrodes. When the inspection area is large and the shape is regular, it shall use qualified fan type electrodes. […]

A.4.3 Detection