MIYAWAKI RE1 User manual

DIRECT ACTING PRESSURE REDUCING VALVE
USER'S MANUAL

SAFETY GUIDE
The model RE1 is a direct acting pressure reducing valve designed
for use in stream lines.
In order to get maximum benefit from this product, be sure to read
this manual before installing it.
The following warnings and cautions are shown at appropriate
places in this manual.
WARNING
Failure to observe this type of precaution may
lead to serious injury or death.
CAUTION
Failure to follow this type of precaution can lead
to injury or damage to equipment and property.
Table of Contents
1 SPECIFICATIONS AND MARKINGS 1
2 CONSTRUCTION DETAILS 2
3 INSTALLATION 3
4 PRESSURE ADJUSTMENT METHOD 9
5 MAINTENANCE 10
6 TROUBLESHOOTING 14
7 WARRANTY 17
8 SERIAL NUMBER (S. No.) DESIGNATION 18
9 GUIDANCE FOR READING SPECIAL PRODUCT NAME 19

1
1 SPECIFICATIONS AND MARKINGS
WARNING
Be sure not to use this product at higher pressures than the specified maximum
operating pressure (PMO) or at temperatures higher than the specified maximum
operating temperature (TMO).
The following items are displayed on the name label or the side of the product.
Check each item to avoid misuse of the product.
1) Primary pressure range (PRIMARY P.): Range of the pressure in the primary side at
which the pressure reducing valve will operate properly.
RE1: 0.2-1.6MPa (29-230psig) RE1-4, RE1-2: 0.2-1.0MPa (29-145psig)
2) Secondary pressure range (SECONDARY P.): The range of reduced pressure on the
secondary side that can be set.
RE1: 0.05-1.0MPa (7.2-145psig), RE1-4: 0.05-0.4MPa (7.2-58psig),
RE1-2: 0.02-0.2MPa (2.9-29psig)
3) Maximum operating temperature (TMO): Maximum temperature at which the
pressure reducing valve will operate properly.
204°C (399°F)
4) Size: 15mm (1/2”), 20mm (3/4”), 25mm (1”)
5) Year of production: The two leftmost digits in the four-digit 'S No.' on the plug (3) are
the last two digits of the year of production.
6) Flow direction: Shown by an arrow.
7) Body material: Brass
8) Model symbol: Showing the product model name
Some pictures and illustrations in this manual are that of the representative model. For
more details regarding dimensions and other specifications, please refer to the catalog.

2
2 CONSTRUCTION DETAILS
RE1
RE1-4
RE1-2
1. Body
3. Plug
4. Valve
5. Valve Seat
6. Bellows
11. Orifice Plate
12. Shaft
13. Stop Ring
16. Return Spring
17. Screen
18. Handle Spring
20. Plug Gasket
21. Seat Gasket
26. Name Label
Handle Unit
2. Cover
8. Main Spring
9. Sleeve
10. Handle
14. Adjust Bolt
19. Taper Pin
22. Cover Gasket
23. Bellows Gasket
24. Name Plate
25. Push Nut
27. Washer
28. Seat

3
3 INSTALLATION
WARNING
 Do not touch the pressure reducing valve, safety valve (relief valve) or the
opening section on the pipe outlet side with your bare hand.
If there is steam present, you may be seriously injured.
 Before supply of steam, check whether there will be any danger if the steam
reaches the end of the pipe and whether all the pipe joints have been connected.
CAUTION
 Before installing the pressure reducing valve on a pipe, discharge all the steam
in the pipe and remove any dirt or scale that may keep the pressure reducing
valve from operating properly.
 Pay attention to the following items when installing the pipes.
1) Remove the dustproof seals covering the inlet/outlet connecting sections of the
pressure reducing valve body.
2) Check the flow direction indicated on the side of the pressure reducing valve body.
3) Be sure to install sections of straight pipe that are at least 10 times longer than the
pipe diameter just before and after the pressure reducing valve (behind the reducer).
4) To avoid reducing the pressure before it reaches the valve, do not install pipes that
reduce the pipe size on the primary side.
5) Install a pressure gauge and a stop valve both before and after the pressure reducing
valve, and always install a bypass line.
Be sure to install a strainer on the primary side (normally 60 - 80 mesh, or 100 mesh in
places where there are lots of scale or dirt present). The strainer should be installed in
such a way that the screen will point sideways to avoid the accumulation of
condensate in the area of the screen. (Refer to the plumbing example described later.)
10 times
or longer
10 times
or longer

4
6) Install a steam trap on the secondary side of the pressure reducing valve so that the
condensate can be discharged when equipment or systems stop being used.
7) The pressure reducing valve should be installed in a horizontal pipe with the operating
part including the adjust unit turned upward.
8) When condensate flows into the pressure reducing valve, hunting or vibration may
occur. Therefore, be sure to install a steam trap just before the pressure reducing
valve.
9) A reducer is recommended when the flow speed is likely to exceed standard (30
m/sec).
Separator
Steam trap
High flow speed
Reducer

5
10) Avoid using the pressure reducing valves in parallel. The pressure reducing valve is
self-actuated type, and each has its own variation in sensitivity and responsiveness
to pressure. Therefore, since two pressure reducing valves cannot be activated
exactly in the same way, only one valve would actually be doing the work. That’s why
they need to be used independently.
11) When the pressure reducing ratio exceeds the maximum pressure reducing ratio,
perform a double pressure reduction. Be sure that the distance between 2 pressure
reducing valves is more than 3 m (9.8 ft).
12) When installing a solenoid valve (ON-OFF valve) on the primary or secondary side of
the pressure reducing valve, install the solenoid valve so that the distance between
the pressure reducing valve and the solenoid valve is 3 m (9.8 ft) or more.
(Otherwise, the pressure reducing valve operation may be unstable.)
Bad example Good example
3 m (9.8 ft)
or more
3 m (9.8 ft)
or more
Solenoid valve

6
13) When using a control valve on the secondary side of the pressure reducing valve,
install the control valve so that the distance between the pressure reducing valve and
the control valve is 2 m (6.6 ft) or more.(Otherwise, the pressure reducing valve
operation may be unstable.)
14) The steam pressure reducing valve does not close fully. Therefore, when the amount
of steam used is close to zero (at the end of service for example), install a steam trap
on the secondary side of the pressure reducing valve.
15) To keep the secondary pressure from rising abnormally, install a safety valve. If
regulations cover the place that the safety valve is installed, use a safety valve which
vents as specified in the regulations. A warning safety valve (relief valve) that is used
to warn of an abnormal pressure rise should be able to blowoff at least 10% more
than the rated flow of the pressure reducing valve.
2 m (6.6 ft)
or more
Solenoid valve
Steam trap
Safety valve (relief valve)
Control valve

7
16) Secure or support the pipe so that any load, bending or vibration in the pipe is not
transmitted directly to the pressure reducing valve.
17) Most complaints about direct acting pressure reducing valves installed in new pipes
or in pipes that have not been used for a long time are due to dirt and scale in the
pipes. Therefore, before sending steam into the pressure reducing valve, blow off the
piping to remove any dirt or scale.
18) When the pressure reducing valve will not be used for a long time, the remaining
pressure in the pipe should be released. Discharge all the condensate from the pipe,
and close the stop valves before and after the pressure reducing valve.
Bypass

8
Plumbing example
Primary
side
Secondary
side
Separator
Pressure
gauge
Stop
valve
Stop valve
Stop valve
Y-type
strainer
Distance of 10
times the pipe
diameter
1m (3.3 ft)
or more
Sight glass
Steam trap DC 1 type
Clearance for Proper Maintenance
When installing the product, be sure
to leave clearance for maintaining it.
Clearance distance shows the
distance from the centerline of the
piping connection.
Distance of 10
times the pipe
diameter
Direct acting
pressure reducing
valve

9
4 PRESSURE ADJUSTMENT METHOD
WARNING
 Since the handle gets hot when the pressure is adjusted, wear work gloves or
leather gloves. Otherwise, you may be burned.
 Do not touch the pressure reducing valve, the safety valve (relief valve) or the
opening section on the pipe outlet side with your bare hand. If there is steam
present, you may be seriously injured.
CAUTION
 After installing the pressure reducing valve, open the bypass valve before
adjusting the pressure and blow all the initial low-temperature condensate, dirt,
scale, etc. out of the pipe.
1） After making sure that each of the stop valves
and bypass valves before and after the
pressure reducing valve are closed:
(1) Pull up gently on the pressure reducing
valve adjusting handle. (2) Turn it clockwise (in
the direction indicated by arrow L) to free the
adjusting spring. (When the spring is free, the
handle will turn easily.)
2） After opening the secondary-side stop valve a
little, open the primary-side stop valve slowly all
the way.
3） (1) Pull up gently on the handle. (2) Turn it
counterclockwise (in the direction indicated by
arrow H). While looking at the pressure gauge,
turn the handle slowly until the required
pressure is attained.
4） When the handle is released, it will be locked in position.
5） Open the secondary-side stop valve fully, and check again the adjusted pressure.
6） In case of a shut-down of the equipment, close the secondary-side stop valve and
then close the primary-side stop valve.

10
5 MAINTENANCE
WARNING
 Before removing the pressure reducing valve from the pipe or disassembling it,
be sure to close the stop valves at the inlet and outlet of the pressure reducing
valve. Then, release the remaining pressure in the pressure reducing valve body
(check whether the pressure in the body has reached 0 MPa (0 bar)), and let it
cool down completely (check whether the surface temperature of the body is at
room temperature). Then, make a safety check and start the maintenance
operation. If there is any pressure or temperature in the pressure reducing valve
body, you may be seriously burned due to the venting of steam or condensate.
CAUTION
 When replacing parts, use maintenance parts supplied by us.
When disassembling the pressure reducing valve body for inspection, refer to section “2)
Disassembly and Reassembly” described later, and work with due care.
1) Inspection
1.1) Inspecting the parts inside the pressure reducing valve
Since it is always necessary to keep the valve, valve seat, sliding section, and the surface
of the screen clean, we recommend that the inside of the pressure reducing valve should
be cleaned regularly. If parts are damaged, replace them with new ones.
Parts to be inspected:
○ Valve section
・Surface of the area between the valve (4) and the valve seat (5)
・Surface of the screen (17)
○ Shaft section
・Sliding section between the shaft (12) and the orifice plate (11)
1.2) We recommend regularly cleaning the screens in the strainers installed around the
pressure reducing valve.
○ Y-type strainers on the primary side of the pressure reducing valve
○ Screens in the steam traps or strainers on the inlet side of the pressure reducing valve

11
2) Disassembly and Reassembly
2.1) Replacing the valve section
○ Disassembly
 When the plug (3) is removed from the bottom of the body (1) using a tool, the screen
(17) can be taken out with the plug (3).
 The return spring (16) and the valve (4) can be removed at this time, together with the
screen (17). (There is a plate on the bottom of the screen (17).)
 Remove the valve seat (5) from the body (1) using a tool.
○ Reassembly
 After replacing the valve seat (5) with a new one, secure the new valve seat (5) in the
body (1).
 After replacing the valve (4) with a new one, put the return spring (16) into the screen
(17), from the large diameter end portion of the return spring. Then, put the new valve
(4) on the small diameter end portion of the return spring, and reinstall them in the
plug (3).
 Secure the plug (3) in the body (1).
RE1-2
Put the curved side of the valve faces the return spring (16) on the small diameter end
portion of the return spring, and reinstall them in the plug (3).
Secure the plug (3) in the body (1), putting the shaft end portion into the hole in the
center of the valve.
Replace the valve seat (5), the plug gasket (20) and the valve seat gasket (21) with new
ones. Before reassembly, put new plug gasket (20) in the gasket grooves in the plug (3).
The valve may be misaligned during assembly. Therefore, after tightening the plug,
remove the handle unit according to the procedure described in the next Step 2.2).
To center the valve (4), push lightly on the end of the shaft (12) several times.
Note)
 Check whether the surface and sealing face of each part are clean, and then attach
them.
 Clean the surface of the screen (17), and attach it. If the screen is deformed or has
flaws, replace it with a new one.

12
2.2) Replacing the bellows and shaft sections
○ Disassembly
 Lift the handle (10) gently, turn it clockwise (in the direction indicated by arrow L) to
free the main spring (8) and then loosen the cover.
 Remove the cover (2) (handle unit), and take out the main spring (8).
 Remove the bellows (6) from the body (1), and take out the shaft (12).
 Remove the stop ring (13) from the groove in the body (1) using the tip of a flat-blade
screwdriver.
 Remove the stop ring (13) and the orifice plate (11) from the body (1).
○ Reassembly
 When replacing the orifice plate (11) with a new one, reinstall it so that the small hole
of the orifice plate is on the outlet side of the body (1).
 Put the bottom of the fold on the stop ring (13) on the face of the orifice plate (11).
Then, push the five edges into the grooved section on the body (1) using the tip of a
flat-blade screwdriver, to secure the orifice plate (11). Do not allow the small hole in
the orifice plate (11) to be blocked by the stop ring (13).
 After replacing the shaft (12) with a new one, insert the spherical surface of the new
shaft into the sliding section of the orifice plate (11). Make sure the shaft (12) moves
smoothly by pushing the end of the shaft (12) lightly several times.
 After replacing the bellows (6) with a new one, reinstall the main spring (8) in the new
bellows (6). Then, reinstall the bellows in the body (1).
Screw the handle unit to the body (1).
Replace the cover gasket (22) and the bellows gasket (23) with new ones.
Put the new bellows gasket (23) in the gasket groove in the body (1).
Note)
 Check whether the surface and sliding face of each part are clean, and then attach
them.
Part
name
Tools
Across the flats
Torque
Cover (2) Torque wrench 65mm (2.56") 120N・m
Valve seat (5) Torque wrench 24mm (0.94") 60N・m
Plug (3) Torque wrench 30mm (1.18") 80N・m
 Apply an anti-seizing agent to the threaded sections.
 Apply a small amount of anti-seizing agent to the threaded sections on the plug (3)
and valve seat (5). However, do not cause the anti-seizing agent to squeeze out of the
seal face.

13
Handle Unit
8. Main Spring
22. Cover Gasket
6. Bellows
23. Bellows Gasket
13. Stop Ring
12. Shaft
11. Orifice Plate
1. Body
21. Seat Gasket
5. Valve Seat
4. Valve
16. Return Spring
17. Screen
20. Plug Gasket
3. Plug

14
6 TROUBLESHOOTING
Symptom
Corrective
action
The primary side pressure
does not increase. ⇒ (1)
The secondary side pressure
does not increase to the set
pressure.
⇒ (2)
The secondary side pressure
increases beyond the set
pressure.
⇒ (3)
The handle cannot be
operated. ⇒ (4)
Chattering occurs. (Vibration
noises from the valve) ⇒ (5)
Steam leaks out. ⇒ (6)
(1) Symptom: The primary side pressure does not increase.
Working
conditions
Cause of the problem Corrective action Reference
item
Due to
plumbing
materials
Shortage of steam volume supplied
to the primary side. (The capacity of
the boiler may be insufficient.)
Recheck the flow rate using the
bypass valve.
-
Review the system.
The stop valve is closed. Open the stop valve.
The pipe on the primary side is too
small.
Review the pipe size.
There is a throttle section in the
primary side pipe
.
Remove the throttle section.
(2) Symptom: The secondary side pressure does not increase to the set pressure.
Working
conditions
Cause of the problem Corrective action Reference
item
Due to
plumbing
materials
Insufficient pressure reducing
valve capacity
Recheck the flow rate using the
bypass valve.
-
Select pressure reducing valve with
the proper capacity.
The difference between the primary
side and secondary side pressures
is below the minimum differential
pressure.
Increase the primary side pressure.
Review the system.
Clogging in the inlet side strainer Disassemble and clean.
The secondary side stop valve is
closed.
Open the stop valve.
The secondary side pipe is too
small.
Review the pipe size.
There is a throttle section in the
secondary side pipe.
Remove the throttle section.
Pressure
gauge
Pressure
reducing valve
Stop valve
Y
-
type
strainer
Stop valve
Pressure
gauge
Bypass valve

15
Working
conditions
Cause of the problem Corrective action Reference
item
Due to
internal
parts
Clogged screen (1
7
)
Clean the screen (1
7
).If it is
damaged, replace it with a new
one.
Item 5-2）-
2.1）
Po
or sliding of the shaft (12)
Clean the sliding section between
the shaft (12) and the orifice plate
(11). If the sliding section is
damaged, replace it with a new
one.
Item 5-2）-
2.2）
(3) Symptom: The secondary side pressure increases beyond the set pressure.
Working
conditions
Cause of the problem Corrective action Reference
item
Due to
plumbing
materials
The consumption on the secondary
side is close to zero.
Install a trap or a safety valve on
the secondary side of the
pressure reducing valve.
-
The inlet or the outlet is installed
incorrectly.
Install them correctly according to
the flow direction.
The bypass valve is not closed.
Pressure is leaking past the bypass
valve.
Close the bypass valve. If the
pressure is leaking, repair or
replace the bypas
s valve.
Due to
internal
parts
Pressure leaks past the valve (4)
due to dirt and scale holding the
valve open.
Clean the surfaces of the valve (4)
and the valve seat (5). If either
surface is damaged, replace the
parts with new ones.
Item 5-2）-
2.1）
Poor sliding of the shaft (12) Clean the sliding section between
the shaft (12) and the orifice plate
(11). If the sliding section is
damaged, replace it with a new
one.
Item 5-2）-
2.2）
Broken bellows (6) Replace the bellows (6) with new
ones.
(4) Symptom: The handle cannot be operated.
Working
conditions
Cause of the problem Corrective action Reference
item
Due to
internal
parts
Mishandling of the handle (10) Pull the handle (10) up gently and
turn it.
Item 4
Sleeve (9) or adjust bolt (14) has
seized.
Replace the handle unit with a new
one. Item 5-2）-
2.2）

16
(5) Symptom: Chattering occurs. (Vibration noise from the valve)
Working
conditions
Cause of the problem Corrective action Reference
item
Due to
plumbing
materials
and internal
parts
Condensate flows in from the
primary side
Install a trap on the primary side of
the pressure reducing valve.
-
Used below the minimum
adjustable flow rate.
Select a new pressure reducing
valve.
Item 5-2）-
2.2）
Poor sliding of the shaft (12)
Clean the sliding section between
the shaft (12) and the orifice plate
(11). If the sliding section is
damaged, replace it with a new
one.
(6) Symptom: Steam leaks out.
Working
conditions
Cause of the problem Corrective action Reference
item
Due to
internal
parts
Loose cover (2) and plug (3) Tighten them to the specified
torq
ue.
Items 5-2)-
2.1) and 2.2)
The plug gasket (20) or the
bellows gasket (23) is broken.
Replace the plug gasket (20) or
bellows gasket (23) with a new one.
Bellows (6) is broken. Replace the bellows (6) with a new
one. Items 5-2)-
2.2)

17
7 WARRANTY
7.1 Warranty period
The warranty period is 18 months after shipment or 12 months after installation, whichever
occurs first.
7.2 Details of the warranty
If the product stops working correctly within the warranty period, we will repair or replace
the product free of charge if the cause of the trouble is not one of the following items.
1) The precautions described in this manual were not observed.
2) User's errors or mistakes such as an inappropriate installation or incorrect handling,
or an excessively large impact caused by dropping
3) Problems caused by devices or equipment other than ours, or a disallowed use
environment
4) When a repair or modification has been performed by anyone other than us or people
who are authorized to make such repairs
5) Intrusion of salt or other substances that promote significant rust or corrosion or
problems from fluids that contain the same substances
6) Consumable parts such as Packing, Gasket, O-ring, Diaphragm, etc
7) Attachment or accumulation of foreign matter in the pipe, such as dust and scale
8) Problems from fires, natural disasters, or other force majeure which is not our
responsibility
7.3 Warranty limitation
The remedy available under the warranty shall not exceed the sales price of the products
delivered, for any cause whatsoever.

18
8 SERIAL NUMBER (S. No.) DESIGNATION
S.No. □□□□
Represents the day.
Represents the month.
Represents the year. (last two digits of the
year according to the Western calendar)
Month designation system
Month
Symbol
Month
Symbol
Month
Symbol
Month
Symbol
1
1
4
4
7
7
X
10
2
2
5
5
8
8
Y
11
3
3
6
6
9
9
Z
12
Day designation system
Symbol
Day
Symbol
Day
Symbol
Day
Symbol
Day
1
1
9
9
H
17
Q
25
2
2
A
10
J
18
R
26
3
3
B
11
K
19
S
27
4
4
C
12
L
20
T
28
5
5
D
13
M
21
U
29
6
6
E
14
N
22
V
30
7
7
F
15
O
23
W
31
8
8
G
16
P
24
Example of serial number designation
1 7 1 1 → Jan 1, 2017
2
9X
M
→
Oct
21, 2029