Electricity + Control June 2018

PRESSURE + LEVEL MEASUREMENT + INSTRUMENTATION

matically fulfil the requirements of pressure test- ing (3) in accordance with the directive 2014/68/ EU. The reverse is not valid. In the following table, the different require- ments are contrasted against each other:

pressure test (3) in accordance with the 2014/68/ EU directive. The pressure equipment directive re- quires only 1.43 times the maximum permissible pressure (PS). As can be seen from the table, in- struments in accordance with EN 837-1 thus auto-

Non-full-scale loadable pressure gauges Full-scale loadable pressure gauges Source

Measurement technology

Duration of overload #1 12 h

12 h

EN 837-1(1)

Overload #1

1 * PFSV

1,3 * PFSV

Duration of overload #2 15 min

–

Overload #2[a]

1,1 – 1,25 * PFSV

–

Changes[a,b] in the class accuracy

1,2 – 1,5 times

1,2 – 1,5 times

Strength (leak tightness)

Duration of the overload

24 h

24 h

EN 837-1(2)

Overload[a]

1,5 – 2,5 * PFSV

1,5 – 2,5 * PFSV

Requirement:

Leak-tight

Leak-tight

Duration of overload –

–

Dir. 2014/68/EU(3)

Overload

1,43 * PS

1,43 * PS

(= 1,07[c] * PFSV)

(= 1,43 * PFSV)

Requirement:

Leak-tight

Leak-tight