Why We Need Hydrocarbons
Table 1. ASME B16.34 Table VII- 2-1. 1
Coal
Temperature
degrees F
History
150 300 600 900 (degrees C)
200
- 20 to 100 285 740 1480 2220
(- 29 to 38)
Quadrillion, Btu
150
Oil
200 (93) 260 680 1360
300 (149) 230 655 1310
100
400 (204) 200 635 1265
500 (260) 170 605 1205
50
600 (316) 140 570 1135
650 (343) 125 550 1100
0
700 (371) 110 530 1060
1980 1990 2003
750 (399) 95 505 1015
Source: EIA
800 (427) 80 410 825
Agency has projected a slight increase
for the year (about 1% at the time of the
workshop but IEA has since revised that
slightly upwards to over 2%). Globally,
demand will increase by 30% by 2025,
but the industrialized world will show
only modest growth while developing
countries will make up the bulk.
850 (454) 65 320 640
mer should be considered by piping
designers and mitigated if at all possible.
Small, screwed soft-seated ball
valves are often made today with WOG
design ratings. Like all elastomer-seated
valves, they are limited in maximum
temperature. The testing criterion for
most WOG ball valves is a shell test at
1. 5 times the WOG rating and a seat
test at 80-100 psi of air.
One development that is “changing
the marketplace and the refining indus-
try,” is the growth of national oil compa-
nies (NOCs, which are companies con-
trolled by governments) and the tendency
toward resource nationalism (protection
of resources) in many of those countries,
Peters said. NOCs now control and pro-
vide limited access to 77% of the world’s
reserves, he pointed out, and some of
those countries (such as Russia,
Most industrial steel or alloy valves
built today are manufactured in accor-
dance with a design standard that is
traceable to ASME B16.34. The
B16.34 document contains tables listing
hundreds of materials and their corre-
sponding working pressures at various
temperatures.
Projections
1500
3705
26 | Valve MAGAZINE
THE EVOLUTION OF RATING
SYSTEMS
Today’s valve pressure ratings are fairly
straightforward; but this has not always
been the case. In fact, the consensus we
have today came about after a long and
winding road.
During the embryonic stages of the
valve industry, valve pressure ratings
were based mainly upon guesswork by
the manufacturer. However, this dead
reckoning had the potential to literally
cause death or injury if the estimated
pressure rating was too high and failure
occurred.
The next step in creating pressure
ratings for valves was to perform burst
tests on the finished product to learn at
33%
2500 4500
27%
26%
6170 11110
Share of world total
2035 3395 5655 10185
1965 3270 5450 9815
Natural Gas
1900 3170 5280 9505
1810 3015 5025 9040
Renewables
9%
1705 2840 4730 8515
5%
Nuclear
1650 2745 4575 8240
1590 2665 4425 7960
2010 2020 2030
1520 2535 4230 7610
1235 2055 3430 6170
In 1949, ASME created an addendum to the original B16e standard,
which contained wall thickness requirements for buttweld end valves of the
various classes. The first pressure-temperature rating standard developed
exclusively for buttweld end valves was
published by the Manufacturers Stan-Venezuela, Iran and China) are using
energy as a diplomatic tool. But even in
Mexico, that country’s state-owned oil
company Pemex is forbidden by the country’s constitution to form partnerships
with any companies that own oil
resources in Mexican territory, Peters
pointed out. Meanwhile, the Arabian
states have a goal of developing their own
gulf area into another Gulf of Mexico
with its accompanying refining power.
955 1595 2655 4785
what pressure the component failed.
After applying some safety factor, the
pressure rating was designated and
applied to the specific valve design.
During the late 19th and early 20th
centuries, valve manufacturers tried to
find a sensible solution by classifying
their valves as standard, medium or
extra heavy. Extra heavy pressure in
1900 was 250 psi of steam.
The Deepwater Horizon disaster and
the uncertainty about what will happen
federally also have potential for chang-
ing the face of where events occur,
Peters said. Personnel already are being
shifted from the U.S. Gulf States by
service and supply companies, and oper-
ating companies are shifting focus from
During the 1920s, the creation of the
first pressure classes improved on this
technique. The valve pressure classes
were an adjunct to these newly created
ASME flange standards. The 300, 600,
900 and 1500 classes were based on the
valve’s working pressure at 750° F
(399° C). The now-common class 150
rating was developed later based on a
temperature of 500° F (260° C). Much
later, the pressure classes of 2500 and
4500 would be added into the mix.
These initial classes were related to the
ratings of the flanges that were a part of
the valve. However, the birth of buttweld
valve development in the late 1930s cre-
ated a bit of a problem because there
were no flanges to relate pressures to.
