MIL-DTL-16356E
4.4.1.4 Shut-off and drain valve securing. Five securing trials shall be made to determine if the valve remains
tight during and after cooling, having closed tight with 15 foot-pounds of torque while hot. Saturated steam at
design pressure shall be applied to the inlet side of the valve. The necessity for taking up on the valve stem to
maintain specified seat tightness shall be noted. More than a 5 foot-pound increase in torque required to maintain
seat tightness and to re-open shall be cause for rejection.
4.4.1.5 Shut-off and drain valve warming. Five warming trials shall be made to determine the torque required
to open the valve after it has been closed tightly when cold.
4.4.1.6 Ball-check steam operation. Five securing trials shall be made to determine if the valve remains tight
during and after cooling, having closed tight with 15 foot-pounds torque while hot. Saturated steam at design
pressure shall be applied to the inlet side of the valve. The necessity for taking up on the valve stem to maintain
specified seat tightness shall be noted. More than a 5 foot-pound increase in torque required to maintain seat
tightness and to re-open shall be cause for rejection.
4.4.1.7 Assembled gauge operation (type A). Minimum requirements of operation test shall be as follows.
Minimum operation of the gauge shall be 1000 hours:
a. Warm gauge at 250 °F per hour to design temperature and pressure with water level maintained at the
mid-point of the visible range.
b. Every 8 to 12 hours cool gauge to ambient temperature at rate of 250 °F per hour to design temperature and
pressure.
c. Every 50 cycles drop pressure from design pressure to 300 psig in 30 seconds maximum and return to
design pressure.
d. Every 20 operation hours maximum while at design pressure, blow down the gauge assembly through the
drain valves.
e.
Every 200 hours, cool to ambient, isolate and drain gauge, and allow to dry for 48 hours.
f.
Repeat steps a through e four additional times.
g. Any additional operational procedure deemed necessary shall be demonstrated once in each 200-hour
period.
h. Boiler and test stand testing shall include 50 warm-ups and cool-downs (see 4.4.1.7.a and 4.4.1.7.b),
4.4.1.8 Type A, class IV gauge, cap screw (bolt) assembly with captive spring cone washers.
4.4.1.8.1 Heat treatment procedure testing. The Temperature Uniformity Survey (TUS) shall use a load that
consists of the FAT spring cone washer lot. In accordance with SAE-AMS 2750 load condition requirements,
sensors may be attached to simulated parts equal to the spring cone thickness of 0.126 to 0.131 inch. A spring cone
washer adjacent to each sensor shall be marked for hardness testing. An equal number of spring cones located
midway between sensors shall also be uniquely marked. After heat treatment the marked samples shall be hardness
tested. Two Rockwell C hardness tests shall be done on each washer 180 degrees apart on the concave face. At the
vendor s option, standard ½-inch wide tensile specimens in accordance with SAE-AMS-2371, cut from the bulk
sheet/strip material used for washer fabrication, may also be included with the semi-finished washers prior to heat
treatment. If necessary, tensile testing can be performed by the vendor to resolve discrepancies in the hardness test
results. Variation in the readings shall not exceed 4 HRC points. No hardness reading shall be less than HRC 42 or
greater than HRC 50. Testing will be considered acceptable if temperature sensors indicate conformance with
SAE-AMS-5520 conditioning and precipitation heat treatment temperatures and holding times are within the
required tolerances, and if the above hardness requirements are met. Hardness readings resulting from acceptable
testing shall be averaged to create a typical hardness value for use as a standard (±2 HRC points) for
production hardness tests.
23
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business