ISO 15848-1 Selection of Temperature Class and target temperature 1

[Cleandive]

With respect to ISO 15848-1
is temperature class = Design temperature?
Should the target temperature be the design temperature of the valve? If so where is it specified or where will it be specified?

Is there any ISO standard or BS EN standard or code (not the client specification) that refers to ISO 15848?

 

[bmoorthy]

6A Valves or 6D Valves or API 600 Valves or ISO 17292 or etc etc

If API 6A, the data sheet will show you the temp classs and this is given in alphabet such as "K", "L" etc K signifies -60, L signifies -46 and so on.

 

[Cleandive]

Valves are not 6A

We have B16.34, API 6D, ISO 17292 valves in our project.

 

[Gilmiril]

The design temperature range must fall within the ISO 15848-1 temperature class to which the valve is qualified. See Table 3 for the defined temperature classes, but note that there is also a caveat that reads, "Alternative temperature classes shall be subject to agreement between the manufacturer and the purchaser." If you're not working to such a special agreement, then you have to test/qualify to the stated temperature classes in the standard.

For example, if you have a valve with a design temperature range to API class P+U (-29C to +121C), then you would have to qualify the valve ISO 15848-1 temperature classes t200C and t-46C (meaning you have to test the high end at 200C or higher and the low end at -46C or lower).

 

[Gilmiril]

I was mistaken in my example above; to qualify a valve that's designed to API temperature class P+U, the low end test need only be at room temperature (RT).

Rereading the original inquiry, in answer to the questions:

"Should the target temperature be the design temperature of the valve? If so where is it specified or where will it be specified?"

No, the target temperatures should be those specified by the temperature classes in Table 3 that cover your design temperature (range). This is confirmed by Clause 6.4, which reads:

6.4 Temperature classes
The target temperature class shall be selected from Table 3. If the test is carried out at any temperature other than those specified in the Table, the next lower class shall apply in case of the test temperature being above zero, or the next higher class shall apply in case of the test temperature being below zero.

EXAMPLE If the test temperature is 405^oC, the value shall be classified as (t400^oC).

All test temperatures shall be recorded in the test report.
-- Test at -196^oC qualifies the valve in the range -196^oC up to RT.
-- Test at -46^oC qualifies the valve in the range -46^oC up to RT.
-- Test at RT qualifies the valve in the range -29^oC to +40^oC.
-- Test at 200^oC qualifies the valve in the range RT up to 200^oC.
-- Test at 400^oC qualified the valve in the range RT up to 400^oC.

To qualify a valve in the range -46^oC up to 200^oC, two tests are necessary:
--The test at -46^oC qualifies the valve in the range -46^oC up to RT;
--The test at 200^oC qualifies the valve in the range RT up to 200^oC.

Alternative temperature classes shall be subject to the agreement between the manufacturer and the purchaser.

The mistake I made in my previous post is that I didn't recognize that their class (tRT) actually covers the range -29^oC to 40^oC.