Precautions to Be Observed When Installing Steam Safety Valves Mounting

Despite the roughhewn outward appearance of safety valves, they are very delicate products comprising precision‐machined internal
components. For that reason, users are encouraged to gain full understanding of safety precautions and the manual. Especially with regard
to safety valve installation, refer to the following cautions, to standards, product manuals, and other materials because failure to do this could
result in leaks, malfunctions, or other problems by imposing an excessive load on a valve, or by piping designs or other configurations that
cause pressure loss. Safety valves also require regular maintenance (every year or every other year). Safety valve care and maintenance
should be left to specialized engineers sufficient training. Our service department provides round‐the‐clock service by full‐time staff
engineers. Please give us a call when you need safety valve maintenance and regular servicing.

■ Safety precautions
The following categories are used to explain the extent of danger damage that is anticipated if cautionary information is ignored products
are incorrectly used.
Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.

Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.

Stay out from under safety valves suspended in the air.

To prevent accidents caused by dropping valves, keep them as near a vertical position as possible when suspending with a crane or other device.
Never go under a suspended valve. Use appropriate equipment after checking the valve’s weight.
Do not use the lever or cap to lift a safety valve.
and Storage
Receiving

Avoid using parts such as the lever or cap to suspend a valve because this could affect valve performance.
We recommend winding a wire or nylon sling around the valve outlet neck and the bonnet or yoke.
Do not let valves tip over.
Many safety valves have curved shapes and are therefore highly unstable. Do not try to stack them in storage because they could tip and be
damaged.
Store safety valves indoors.
Safety valves should be kept indoors when in storage before mounting. If indoor storage is impossible, shroud completely wi h a waterproof tarp or
other covering to prevent exposure to the elements.
Mount the safety valve directly on the mounting connection in an upright position.
Mount the valve in an upright position on the boiler or the mounting connection. Mounting an incline could cause poor tightness and unstable
operation. The permissible deviation from the vertical is within ±1°.
Use care in tightening the flange bolts.
When mounting a safety valve, first remove the inlet and outlet protective covers and make sure there is no foreign matter. When mounting a flanged
valve, be sure that the flange gasket dose not protrude, and tighten the flange bolts alternately to ensure they are all tightened equally.
Improper bolt tightening could cause steam leaks and pose the danger of burns by leaked steam.
Installing Steam Safety Valves Mounting

The safety valve inlet connection must be at least as large as the valve inlet diameter.
The inside of the safety valve’s mounting connec ion should save rounded corners and its inside diameter should be at least the same as the valve’s
Precautions to Be Observed When

nominal to ensure the smooth flow of steam from the boiler to the valve. We recommend that the R dimension of the inlet pipe’s inside diameter
corner is at least one‐fourth the inside diameter.
Pressure loss at the safety valve inlet should be under 2%.
See that the pressure loss from the connection to the valve is under 2% of the valve’s set pressure. A large pressure loss presents the danger of
chattering when the valve operates.
When a valve is installed on an elbow, provide for a generous radius as well as appropriate supports for curved attachments.
Mount safety valves a sufficient distance away from joints and other valves.
When installing a safety valve on a pipe line, make sure it is sufficiently distant from joints or other valves that disrupt the fluid flow. A safety valve
must be at least the approximate distance of 10 X D (where D is pipe diameter) from these other fixtures, both upstream and downstream. Do not
install a branch‐pipe in a position that is symmetrically opposite the safety valve. When installing two or more safety valves on the same header or
line, be careful of the distance between valves. A malfunction could result from unevenness in the pressure distribution if all safety valves actuate at
same time.
Be careful of safety valve blowoff recoil.
A exhaust pipe’s diameter must be at least as large as the safety valve’s outlet diameter, and the distance from the valve axis to the center of the
exhaust pipe must be less than four time the ou let diameter. The pipe must be as short as possible and lead outdoors without bends; its structure
must be as simple and sound as possible. Back pressure arising in the exhaust pipe when the valve operates must not exceed 10% of the set
pressure because it could cause unstable operation. Adopt piping arrangements that will not allow excessive impacts on the safety valve from
thermal expansion of the boiler, other equipment and the exhaust pipe, or other causes. If you attach a drain pipe to the exhaust pipe, make sure the
end is open.
Do not restrict safety valve actuation with drain pipe.
Be sure to provide a safety valve with a drain pipe to drain away rainwater, and the condensed water that forms during a safety valve blowoff. Take
care to provide a drain pipe that is independent of other piping, and does not restrict the valve. Leave the lower end open; do not attach a cock or
valve.
Be careful of test pressure when performing hydrostatic pressure tests.
When pressure testing a safety valve, carefully watch the test pressure and be sure never to exceed it. Some valves have a water pressure plug un
the nozzle seat for pressure testing. Be sure to remove the plug after testing but before starting operation. See the manual for details.
Use a safety valve’s lever only when necessary.
Do not touch or lift a safety valve’s lever except when there is a need to use it. Unnecessary use could cause improper functioning.
Operation and Use

Do not use safety valve as a foothold.

Never use an installed safety valve as a foothold when performing a task. This could damage the valve, and is also dangerous should the valve
operate.
Carefully choose where safety valves are installed.
If a safety valve is installed near a heat source, or where it is exposed to a cold air current, such external thermal influence could cause uneven
expansion or contraction, bringing about a malfunction or poor tightness. In such a case, change the installation location, provide for heat retention,
and take other measures. If lagging is used, cover the valve midsection down to the bottom, taking care not to cover the adjustment lock bolts.
Be careful of pressure when removing or dismantling a safety valve.
When removing a safety valve for regular servicing or other purposes, or dismantling a valve in a condition of being installed on equipment, begin
work only after making sure there is no internal pressure in order to eliminate the danger of a serious accident.
Provide access space around a safety valve.
Leave open space around a safety valve to facilitate dismantling, inspection, and adjustment. Dismantling requires open space above a valve as
well, so make sure it is possible to attach a chain block for lifting a valve.
 Ｓ Ｊ/ Ｓ Ｌ１ （ ）９～３（ ） ９ Series Parts Materials

Type ＳＪ（ ）３（ ） ＳＪ（ ）５（ ） ＳＪ（ ）６（ ）

４００゜Ｃ ５１０゜Ｃ ５３８゜Ｃ

Maximum Temperature
７５０゜Ｆ ９５０゜Ｆ １０００゜Ｆ
Nozzle *1 SA105M SA182M-F12 SA182M-F22

Disc SUS630 (≦320℃ ) or B637-N07750 (＞320℃ )

Disc Collar SUS630

Holder SUS420J2

Body SA216M-WCB SA217M-WC6 SA217M-WC9

Yoke SA216M-WCB SA217M-WC6

Yoke
Spindle Guide SUS630

Spindle SUS403 SUS431

Guide SUS420J2 or SCS1

Upper or Lower Ring SUS304 or SCS13A

Upper Lock Bolt SUS403 SUS431

Parts Name

Lower Lock Bolt SUS403 SUS431

Upper or Lower Spring Washer SUS403

Spring Carbon Steel or Alloy Steel

Adjusting Screw SUS420J2

Adj. Screw Lock Nut SUS304

Lift Stopper SUS420J2

Step Ring SUS420J2

Stud Bolt & Nut SNB7 / S45C SNB7 / S45C

Cap FCD450-10

Fork Lever FCMB310-8

Easing Lever FCMB310-8

Pin SUS304

Adjust Needle／Adj. Lock Nut *2 SUS304 / SS400

Adjustment Valve *2 SCS13

*1：Bishilite deposited on the seat surface.
*2：Either the back pressure adjustment needle or the back pressure adjustment valve is the manufacturer
standard for the back pressure adjustment mechanism.

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