Types 95L, 95H, 95HP, and 95HT
5
from NPS 1/4 through 1 (DN 25) with a variety of
end connections. The standard orifice sizes are 1/4,
3/8, and 9/16-inch (6,4; 9,5; and 14 mm) diameter,
dependent on body sizes.
Type 95H
—Basically the same as Type 95L, but
permits higher outlet pressure ranges from 15 to
150 psig (1,0 to 10,3 bar) for the NPS 1/4, 1/2, 3/4, and
1 (DN 15, 20, and 25) sizes. Also available in
NPS 1-1/2 and 2 sizes with a 1-1/16-inch (27 mm)
orifice to give outlet pressure ranges from 5 to 150 psig
(0,34 to 10,3 bar).
Type 95HP
—Basically the same as Type 95H, but
permits even higher outlet pressure ranges from 15 to
400 psig (1,0 to 27,6 bar).
Type 95HT
—Basically the same as Type 95H, but
permits higher outlet pressures at higher temperatures.
Outlet pressure ranges are available from 15 to 300 psig
(1,0 to 20,7 bar) and temperatures up to 650°F (343°C)
.
Principle of Operation
The 95 Series (refer to Figure 2) is a direct-operated
regulator. Downstream pressure is registered
internally through the body to the under side of the
diaphragm. When the downstream pressure is at or
above the set pressure, the disk is held against the
orifice, and there is no flow through the regulator.
When demand increases, downstream pressure drops
slightly allowing the spring to extend, moving the stem
down and the disk away from the orifice. This allows
flow through the body to the downstream system.
Types 95H, 95L, 95HP, and 95HT use spring force to
regulate outlet pressure.
Installation
Clean out all pipelines before installation of the
regulator and check to be sure the regulator has not
been damaged or collected foreign material during
shipping. Apply pipe compound to the external pipe
threads and install the regulator in any position desired,
but be sure flow through the body is in the direction
indicated by the arrow cast on the body.
Note
It is important that the regulator be
installed so that the vent hole in the
spring case is unobstructed at all times.
For outdoor installations, the regulator
should be located away from vehicular
traffic and positioned so that water, ice,
and other foreign materials cannot enter
the spring case through the vent. Avoid
placing the regulator beneath eaves or
downspouts, and be sure it is above the
probable snow level.
On NPS 1-1/2 or 2 (DN 40 or 50) 95H Series
regulators, the spring case vent is tapped so a vent
line can be connected to provide venting to a remote
location. On NPS 1/4, 1/2, 3/4, and 1 (DN 15, 20, and
25) 95H Series body sizes, the tapped vent option is
available on request. The exposed end of the vent
pipe should be protected with a weather and insect
resistant vent assembly.
All vents and remote vent lines should be checked
periodically to ensure that they are unobstructed.
Overpressure Protection
The Types 95L, 95H, 95HP, and 95HT regulators
have an outlet pressure rating lower than the inlet
pressure rating. The recommended pressure
limitations are stamped on the regulator nameplate.
Some type of overpressure protection is needed if the
actual inlet pressure exceeds the maximum operating
outlet pressure rating. Overpressure protection
should also be provided if the regulator inlet
pressure is greater than the safe working pressure of
downstream equipment.
Some type of external overpressure protection should
be provided if inlet pressure will be high enough to
damage downstream equipment. Common methods
of external overpressure protection include relief
valves, monitoring regulators, shutoff devices, and
series regulation.
Regulator operation below the maximum pressure
limitations does not preclude the possibility of
damage from external sources or from debris in
the pipeline. If the regulator is exposed to an
overpressure condition, it should be inspected for any
damage that may have occurred.
Startup
The regulator is set at the factory for the setpoint
specified on the order, so no initial adjustment should
be required to give the desired results. With proper
installation completed and relief valves properly
adjusted, slowly open the upstream and downstream
shutoff valves.
Adjustment
The factory setting of the regulator can be varied within
the pressure range stamped on the nameplate. To
