INTERNATIONAL STANDARDS USED IN THE
DESIGN OF BALL VALVES
The design of ball valves involves the use of many international standards for producing highquality products. These standards cover the materials, dimensions, tolerances, and marking for
ball valves, ensuring that they can handle the pressures and temperatures they are designed
for. Different countries use different standards which makes it important for the manufacturer
located anywhere in the world to design and produce the proper product. Essentially, the
functional design of the valve is fairly common though the end connections are country-specific
or region-specific.
For example, the projects executed by American companies normally have NPT threaded
valves whereas the projects by European companies have BSP threaded valves. Similarly, the
flanged connections on valves follow ASME or DIN standards depending upon American or
European contractors. The Japanese have their own flange standards prefixed with JIS.
The British standard BS5351 was used extensively for ball valve design until it was replaced by
ISO 17292 standard.
API 6D is the American equivalent standard for ball valve design. Both the standards are similar
in content except for some minor differences.
In India, we generally use ISO 17292 standard in conjunction with ASME B16.34 standard.
ISO 17292 provides all the necessary information, namely, bore diameters for reduced and fullbore ball valves as per pressure classes, the basic structure of ball valves for both floating and
trunnion mounted, butt weld end and socket weld end dimensions, ball and stem design, seat
selection depending upon temperature, testing procedure, markings on valves, etc.
ASME B16.34 standard provides the wall thickness details depending upon the material of
construction, pressure class, and temperature of operation of the valve.
Most ball valves used in India come with ASA flanges which have dimensions as per ASME
B16.5 standard. This standard provides the dimensions of flanges depending upon the pressure
class and size of the valve. Under the ASA regime, the pressure classes are specified by
numbers such as 150#, 300#, 600#, 1500#, and 2500#. Each pressure class is suitable for
working in a specific pressure and temperature range.
DIN standards follow a more straightforward approach. The pressure classes are denoted as
PN10, PN16, PN25, PN40, PN100, etc. which represent maximum working pressures in the
bar.
There are projects executed by European contractors which have ball valves with DIN flanges.
Replacement of DIN flanged ball valves with more commonly available ASA flanged ball valves
require one-time replacement of pipeline flanges with suitable ASA flanges.
The distance to be maintained between two pipeline flanges is decided by the face-to-face
length of the ball valve. This length is provided by ASME B16.10 standard. Valves
manufactured in accordance with ASME B16.10 standards can be fitted and replaced with
similar valves onto the pipelines whenever required.
Testing procedure for ball valves prior to dispatch is specified in BS6755 Part 1 and Part 2.
BS6755 Part 1 gives the testing procedure for normal ball valves.
BS6755 Part 2 gives the Fire Safe Test procedure.
Similarly, API 598 provides the required information for valve testing.
API 607 provides the Fire safe test procedure.
Other important standards are ISO 5211 which provides the dimensional details for actuator
mounting pads provided on valves.
NACE MR0175 provides the requirements for crack-resistant material to be used in oil and gas
environments containing H2S.
ASME B16.11 standard gives the dimensional details for threaded ends and socket weld ends
for fittings.