YAMADA NDP-P50 User manual

MAINTENANCE MANUAL
YAMADA AIR-OPERATED DOUBLE DIAPHRAGM PUMP
NDP-P50
Doc. No. NDP 476M-03

WARNING
• For your own safety, be sure to read these procedures carefully before performing
maintenance on this product. After reading this document, be sure to keep it handy for
future reference.
This maintenance manual covers what you should know about maintenance of the Yamada NDP-P50
series Diaphragm Pumps.
This edition is based on the standards for the July 2020 production run. Remember, the specifications are
always subject to change; therefore, some of the information in this edition may not apply to new
specifications.
∙Warnings and Cautions
For safe use of this product, be sure to note the following: In this document, warnings and cautions are
indicated by symbols. These symbols are for those who will operate this product and for those who will be
nearby, for safe operation and for prevention of personal injury and property damage. The following
warning and caution symbols have the meanings described below. Be sure to remember their meanings.
If you ignore the warning described and operate the product in
an improper manner, there is danger of serious bodily injury or
death.
If you ignore the caution described and operate the product in an
improper manner. There is danger of personal injury or property
damage.
Furthermore, to indicate the type of danger and damage, the following symbols are also used along with
those mentioned above:
This symbol indicates a DON'T, and will be accompanied by an explanation on something
you must not do.
This symbol indicates a DO, and will be accompanied by instructions on something you
must do in a certain situation.
WARNING
• Before starting maintenance work, cut off the feed air and clean the pump. If air pressure or
residue remain in the pump, there is danger of explosion, or possible poisoning resulting
in serious injury or death if chemicals adhere to the skin or are accidentally swallowed.
(For details on cleaning the pump, refer to Chapter 6 of the Operation Manual.)
• When replacing parts, be sure to use the recommended genuine parts or Equivalents. Use of
other parts may cause a malfunction of the product.
(Refer to Parts list the separate sheets.)
CAUTION
• When it is instructed that special tools must be used, be sure to use the specified tools.
Otherwise, the pump may be damaged.
• Refer to “10.1 Specifications” in the Operation Manual. Also, remember that the pump is
heavy, and extreme care must be taken when lifting it.
• Stainless steel bolts and nuts are used to fix the casing. Use anti-seize lubricant when
screwing these.
WARNING :
CAUTION :

Table of Contents
∙Warnings and Cautions
∙
Table of Contents
1. Principles of operation------------------------------------------------------------ 1
2. Maintenance and Tools
2.1 Maintenance ------------------------------------------------------------------------ 1
2.2 General tools ----------------------------------------------------------------------- 1
2.3 Special tools ------------------------------------------------------------------------ 1
2.4 Misc. ---------------------------------------------------------------------------------- 1
3. Ordering Replacement parts--------------------------------------------------- 2
4. Balls and Valve seats
4.1 Removal ------------------------------------------------------------------------------ 2
4.2 Inspection --------------------------------------------------------------------------- 3
4.3 Installation ------------------------------------------------------------------------- 3
5. Diaphragm and Center rod
5.1 Removal ------------------------------------------------------------------------------ 4
5.2 Inspection --------------------------------------------------------------------------- 5
5.3 Installation ------------------------------------------------------------------------- 5
6. Throat bearing and Pilot valve Assembly
6.1 Removal ------------------------------------------------------------------------------ 7
6.2 Inspection --------------------------------------------------------------------------- 7
6.3 Installation ------------------------------------------------------------------------- 7
7. C Spool Valve Assembly
7.1 Removal ------------------------------------------------------------------------------ 8
7.2 Inspection --------------------------------------------------------------------------- 9
7.3 Installation ------------------------------------------------------------------------- 9
8. Retightening of Tie rods ------------------------------------------------------- 10

1
1. Principles of operation
There are two diaphragms fixed to the center rod, one at each end. When compressed air is supplied to air
chamber b (right side, see Fig.1.1), the center rod moves to the right, the material in material chamber B is
pushed out, and at the same time material is sucked into material chamber A.
When the center rod is moved full-stroke to the right, the air switch valve is switched, compressed air is
sent to air chamber a (left side, see Fig.1.2), and the center rod moves to the left. The material in material
chamber A is pushed out, and at the same time material is sucked into material chamber B.
Through repetition of this operation, material is repeatedly taken in and discharged out.
2. Maintenance and Tools
2.1 Maintenance
Pump maintenance is recommended after each of the following periods.
Estimated inspection timing (Based on water at room temperature)
Type of diaphragm Operation hours (h) Type of diaphragm Operation hours (h)
CR 1100 PTFE 200
NBR 1100 TPEE 1600
EPDM 1100 TPO 1600
FKM 250
* In critical operations where preventive measures need to be taken, it is recommended to inspect
diaphragms after every three months of operation.
2.2 General tools
· Socket wrenches 13mm, 17mm, 19mm
· Hexagonal box wrenches 6mm
· Small crowbars 2 (B□C, B□N, B□E, B□V)
· Open-end wrenches 19mm, 24mm
· Plastic hammer · Phillips head screw driver · Ajustable angle wrenches · Needle Nose Pliers
2.3 Special tools
· PPwrench(soldseparately) · Sleeve remover (sold separately)
Purpose:Removingthecenterdisk Purpose:Forremovingsleeve
2.4 Misc.
· Assembly oil Turbine oil none addition class 1(equivalent ISO VG32 grade)
· Nuts M16
X 1.5
· Thread locker
· Grease Urea grease grade (NLGI) No. 2

2
3. Ordering Replacement parts
For accurate and speedy shipment of parts, be sure to order the right parts for your model to distributor.
Indicate the part numbers, descriptions, and quantities.
4. Balls and Valve seats
4.1 Removal
▪Remove the 6 retainer bolts “1” from the out manifold, and
remove the protector and out manifold.
▪Remove the Silencer. [Fig.4.1]
▪Remove the ball, valve seat and O ring. [Fig.4.2]
▪Remove the 6 retainer bolts “2” from the in manifold, and
remove the protector and in manifold. [Fig.4.1]
▪Remove the ball, valve seat and O ring. [Fig.4.3]
Fig.4.2
Fig.4.3
①
②
Fig.4.1

3
4.2 Inspection
▪Ball [Fig.4.4]
Measure the outside diameter, and if it is outside the usable
range, replace the ball.
Usable range of ball
SØ56.7 - Sø64.9 mm
▪Valve seat [Fig.4.5]
Measure the dimension shown at left, and if it is outside the
usable range, replace the seat.
Usable range of valve seat
B
□
C , B
□
N, B
□
E
B□V, B □H, B□S, B□H/T
B□T
5.0 - 12.5 mm
1.7 - 4.1 mm
▪O ring (other than PTFE)
If O ring is worn out or cracked, replace it.
4.3 Installation
For installation, see [Exploded View] on the separate sheet and install in the reverse order of
disassembly.
Tightening torque for manifold retainer bolts
25 N•m
<NOTE>
▪Make sure there is no dust on the seal surface and the seal
is not damaged.
▪Replace the PTFE O ring regardless of its condition.
▪Match the convex and concave parts of the protector.
[Fig.4.6]
Fig.4.6
Fig.4.5
Fig.4.4

4
5. Diaphragm and Center rod
5.1 Removal
▪Remove the ball etc. (see “4.1 Removal”).
▪Remove the 8 retainer bolts from the stand body, and remove
the stand body. [Fig.5.1]
・Unscrew 16 bolts (include 8 bolts mentioned above) from the
out chamber and remove the out chamber.[Fig.5.2]
▪Remove the center disk from one side using the PP wrench
(special tool: Part No. 771868). [Fig.5.3]
▪After the center disk (outside) has been removed, remove the
diaphragm and the center disk (inside).
Remove the center disk and center rod from the opposite side
of the main body.
▪Fix a double nut to one end of the center rod and take the
diaphragm and center disk off the opposite end. [Fig.5.4]
Be careful not to scratch or score the center rod.
Fig.5.4
Fig.5.2
Fig.5.3
Fig.5.1

5
5.2 Inspection
▪Diaphragm
If the diaphragm is worn out or damaged, replace it.
Never replace just one diaphragm.
▪Center rod [Fig.5.5]
Measure the diameter, and if it is outside the usable range,
replace the rod.
Usable range of center rod
Ø 24.93 - Ø 25.00 mm
5.3 Installation
■B□C, B□N, B□E, B□V, B □H, B□S, B□H/T types
For installation, see [Exploded View] on the separate sheet and install in the reverse order of
disassembly.
▪Apply assembly grease to the center rod, and insert it into
the main body.
▪Insert the cushion.
▪Keep the marking “OUTSIDE” to liquid end for CR, NBR,
EPDM, FKM diaphragms. Keep the convex side to the
outside for TPEE, TPO diaphragms.
▪Apply threadlocker to center rod and tighten the center disk
by the PP wrench (special tool, part number 771868).
Tightening torque for center rod
50 N•m
Fig.5.6
Fig.5.5

6
▪Draw the center disk to one side (exclude B□H, B□S,
B□H/T type cf.Fig.5.6).
▪And install the out chamber. Tighten the bolts temporarily.
▪Grip the inside center disk using crowbars and draw it to the
opposite side, then turn the diaphragm over.
(exclude B□H, B□S, B□H/T type) [Fig.5.7, 5.8]
▪And install the out chamber. Tighten the bolts temporarily.
▪After installation of the out chambers on both sides, place
the pump on a flat surface and stand the pump upright for
further assembly.
Tightening torque for out chamber.
35 N•m
<NOTE>
▪Make sure there is no dust on the seal surface in order to
prevent seal damaged.
▪Be careful not to damage the R portion and serrations of the
air chamber using a crowbar, etc.
▪Tighten the bolts gradually in a diagonal sequence with even
torque. [Fig.5.9]
■B□T type
For installation, see [Exploded View] on the separate sheet and install in the reverse order of disassembly.
▪Apply assembly grease to the center rod, and insert it into
the main body.
▪Keep the convex side to the outside (cf. Fig.5.10).
▪Put the O rings to both sides of the diaphragm. (cf. Fig.5.10)
▪Apply thread locker to center rod and tighten the center disk
by the PP wrench (special tool, part number 771868).
Tightening torque for center rod
50 N•m
▪Tighten the out chamber temporarily at first.
After installation of the out chambers on both sides, place
the pump on a flat surface and stand the pump upright for
further assembly.
Tightening torque for out chamber
35 N•m
<NOTE>
▪Make sure there is no dust on the seal surface in order to
prevent seal damaged.
▪Replace the PTFE O ring by new one.
▪Tighten the bolts gradually in a diagonal sequence with even
torque. [Fig.5.11]
Fig.5.9
Fig.5.11
Fig.5.8
Fig.5.10
Fig.5.7

7
6. Throat bearing and Pilot valve assembly
6.1 Removal
▪Remove the diaphragm and center rod (see “5.1 Removal”).
▪Unscrew 12 bolts (①) and 8 tapping screws (②), and remove
the air chamber. [Fig.6.1]
▪Pull the pilot valve and valve seat out. [Fig.6.2]
▪Pull the throat bearing out. [Fig.6.2]
*Push these out from the other side if cannot be removed.
▪Remove the packing from the throat bearing. [Fig.6.3]
6.2 Inspection
▪Throat bearing [Fig.6.4]
Measure the inside diameter, and if it is outside the usable
range, replace the throat bearing
Usable range of throat bearing
Ø 25.04 - Ø25.13mm
▪O ring, Packing
If the O ring is worn out or cracked, replace it.
▪Pilot valve
If the pilot valve is worn out or cracked, replace it.
6.3 Installation
For installation, see [Exploded View] on the separate sheet and install in the reverse order of
disassembly.
Tightening torque for air chamber retainer bolts
20 N•m
Tightening torque for tapping screws
5 N•m
<NOTE>
▪Make sure there is no dust on the seal surface and the seal
is not damaged.
▪Apply grease to packing.
Fig.6.3
Fig.6.4
Fig.6.5
Fig.6.2
Fig.6.1
①
②

8
7. C spool valve assembly
7.1 Removal
▪Remove the 4 cap A and cap B retainer bolts, and remove cap
A and cap B. [Fig.7.1]
▪Draw out the C spool valve assembly, and remove the
seal ring from the C spool valve assembly.
▪Remove the spring stopper. [Fig.7.2]
▪Remove the sleeve using the sleeve remover (special
tool: Part number 713180). [Fig.7.3]
Fig.7.1
Fig.7.2
Fig.7.3

9
7.2 Inspection
▪C Spool Valve Assembly
Seal ring [Fig.7.4]
Measure the inside thick diameter, and if it is outside the
usable range, replace the C Spool Valve Assembly.
If the seal ring is worn out or cracked, replace C Spool Valve
Assembly.
Usable range of Seal ring
3.77 - 3.85 mm
▪Sleeve Assembly [Fig.7.5]
Measure the inside diameter, and if it is outside the usable
range, replace the c spool valve assembly.
Usable range of sleeve
Ø 33.15 -Ø 33.35 mm
▪O ring
If the O ring is worn out or cracked, replace it.
<NOTE>
▪C Spool Valve Assembly must be replaced as a complete set.
Unable to replace individual component.
7.3 Installation
For installation, see [Exploded View] on the separate sheet and install in the reverse order of
disassembly.
▪Install the sleeve using the sleeve remover (special tool: Part
No. 713180). At this point, apply assembly oil around the
sleeve and O ring.
▪Install the sleeve at the center of the valve body. (A = B)
Tightening torque for installation cap A, cap B
5 N•m
<NOTE>
▪Make sure there is no dust on the seal surface and it is not
damaged.
Fig.7.6
Fig.7.4
Fig.7.5

10
Fig.8.2
8. Retightening of Tie rods
▪All bolts should be retorqued:
(1) Right before start up.
(2) There are any leaks of material on daily inspecting a pump.
<NOTE>
▪Retighten the Out chamber and then the manifold in this order.
[Fig.8.1]
▪Tighten the bolts in the order shown. [Fig.8.2]
Retain bolts for the
out chamber
Retain bolts for
the manifold
35 N
･
m
20 N
･
m
Fig.8.1

YAMADA EUROPE B.V.
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PHONE : [phone]
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Manufactured by
YAMADA CORPORATION
INTERNATIONAL DEPARTMENT
1-1-3, Minami-Magome,Ota ku, Tokyo, 143-8504, Japan
PHONE : [phone]
FAX : [phone]
E-mail : [e-mail]
Web : www.yamadacorp.co.jp
202009.2479 NDP476M