YAMADA NDP-5 series User manual

MAINTENANCE MANUAL
YAMADA AIR-OPERATED DOUBLE DIAPHRAGM PUMP
NDP-5
NDP-15
Doc. No. NDP 183M-09

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-5 series
and NDP-15 series Diaphragm Pumps.
This edition is based on the standards for the May 2015 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 Exploded View and Reminder to order correct item on 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.
WARNING:
CAUTION :

Table of Contents
·Warnings and Cautions
·Table of Contents
1.Principles of operation------------------------------------------------------------1
2.Tools, etc.
2.1 General tools-----------------------------------------------------------------------1
2.2 Special tools------------------------------------------------------------------------1
2.3 Misc. ---------------------------------------------------------------------------------1
3.Ordering Replacement parts ---------------------------------------------------1
4.Balls, Flat valves and Valve seats
4.1 Removal
■FAT, FST, BA□, BS□, BPS types -------------------------------------------2
■FP□, FV□, FDT types ---------------------------------------------------------3
4.2 Inspection
■Ball valve types ------------------------------------------------------------------4
■Flat valve types ------------------------------------------------------------------4
4.3 Installation-------------------------------------------------------------------------4
5.Diaphragm and Center rod
5.1 Removal
■FAT, FST, BA□, BS□, BPS types -------------------------------------------5
■FP□, FV□, FDT types ---------------------------------------------------------6
5.2 Inspection --------------------------------------------------------------------------6
5.3 Installation
■B□H, B□S, FPH, FPS
types-------------------------------------------------7
■B□C, B□N, B□T, FPC, FPN, F□T
types --------------------------------7
6.Pilot valve Assembly, Guide and Bushing
6.1 Removal
■NDP-5 -------------------------------------------------------------------------------8
■NDP-15 -----------------------------------------------------------------------------8
6.2 Inspection --------------------------------------------------------------------------8
6.3 Installation-------------------------------------------------------------------------8
7.C spool valve Assembly and Sleeve Assembly
7.1 Removal -----------------------------------------------------------------------------9
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.Tools, etc.
2.1 General tools
▪Socket wrenches 10mm( NDP-5 ), 13mm( NDP-15 )
▪Open-end wrenches 10mm ( NDP-5 ), 13mm( NDP-15 ), 21mm( NDP-15 )
▪Plyer
2.2 Special tools (sold separately)
▪Cap and disk remover ▪Sleeve remover
Purpose: Removing the center disk of Purpose: For removing sleeves
FP□and FVT and FDT types
2.3 Misc.
▪Assembly oil Turbine oil none addition class 1( equivalent to ISO VG32 grade )
▪Nuts M6X 1( NDP-5 ), M8 X 1.25( NDP-15 )
▪Grease Urea grease grade (NLGI) No.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.

2
4. Balls, Flat valves and Valve seats
4.1 Removal
■FAT, FST, BA□, BS□, BPS types
▪Remove the 4 retainer bolts from the out manifold, and
remove the out manifold. [Fig.4.1]
▪Remove the O ring, valve stopper, valve guide, flat valve and
valve seat. (NDP-5) [Fig.4.2]
▪Remove the O ring, valve guide, ball and valve seat.
(NDP-15) [Fig.4.2]
▪Turn over the main body assembly. [Fig.4.3]
▪Remove the 4 retainer bolts from the in manifold, and
remove the base and in manifold. [Fig.4.3]
▪Remove the O ring, valve seat, flat valve, valve guide and
valve stopper. (NDP-5) [Fig.4.4]
▪Remove the O ring, valve seat, ball and valve guide.
(NDP-15) [Fig.4.4]

3
■FP□, FV□, FDT types
▪Remove the 4 retainer nuts from the out manifold, and
remove the out manifold. [Fig.4.5]
<NOTE >
▪When the retainer nuts both side of the tie rod remove,
the in manifold removes.( NDP-5 )
▪Remove the O ring, valve stopper, flat valve and valve seat.
[Fig.4.6]
▪Turn over the main body assembly. [Fig.4.7]
▪Pull out the bolt, and remove the base and in manifold.
(NDP-5 )
▪Remove the 4 retainer bolts from the in manifold, and
remove the base and in manifold. ( NDP-15 ) [Fig.4.7]
▪Remove the O ring, valve seat, flat valve and valve stopper.
[Fig.4.8]

4
4.2 Inspection
■Ball valve type
▪Ball [Fig.4.9]
Measure the outside diameter, and if it is outside the usable
range, replace the ball.
Usable range of Ball
NDP-15 SØ 20.0 ~ SØ 22.8 mm
▪Valve seat [Fig.4.10]
Measure the dimension shown at left, and if it is outside the
usable range, replace the seat.
Usable range of Valve seat
NDP-15 2.6 ~ 5.7 mm
■Flat valve type
▪Flat valve [Fig.4.11]
Measure the dimension shown at left, and if it is outside the
usable range, replace the seat. If the seal ring is worn out or
cracked, replace it.
Usable range of Flat valve
NDP-5 2.5 ~ 3.1 mm
NDP-15 4.3 ~ 5.0 mm
▪Valve seat [Fig.4.12]
Measure the dimension shown at left, and if it is outside the
usable range, replace the seat.
Usable range of Valve seat
NDP-5 5.8 ~ 7.1 mm
NDP-15 8.2 ~ 10.0 mm
▪O ring (other than PTFE)
If O rings 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 or nuts
NDP-5 7.5 N•m
NDP-15 12 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.

5
5. Diaphragm and Center rod
5.1 Removal
■FAT, FST, BA□, BS□, BPS types
▪Remove the ball or flat valve and valve seat (see [4.1
Removal FAT, FST, BA□, BS□, BPS types]).
▪Remove the 8 (12 on the NDP-15) retainer bolts from the out
chamber, and remove the out chamber. [Fig.5.1]
▪Remove the nuts on both sides of the center rod. [Fig.5.2]
▪After the nuts on one side have been removed, remove the
center disk and diaphragm. Remove the diaphragm, center
disk and center rod from the opposite side of the main body.
<NOTE>
▪When the diaphragms are removed, the main body is
separated 2 pieces. For easy work, leave the tie rods or bolts
fastened temporarily before remove the diaphragms.
▪Remove the nuts on the opposite side using the double nuts.
[Fig.5.3]
▪Remove the coned disk spring, center disk and diaphragm.

6
■FP□, FV□, FDT types
▪Remove the flat valve and valve seat
(see [ 4.1 Removal FP□, FV□, FDT types] on P.3).
▪Remove the 8 (12 on the NDP-15) retainer nuts from the
out chamber, and remove the out chamber. [Fig.5.4]
▪Remove the center disk using the cap and disk remover.
(special tool: Part No. 771132). (NDP-5) [Fig.5.5]
▪Remove the center disk from one side.(NDP-15) [Fig.5.5]
▪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.
<NOTE>
▪When the diaphragms are removed, the main body is
separated 2 pieces. For easy work, leave bolts fastened
temporarily before remove the diaphragms.
▪Fix a double nut to one end of the center rod and take
the diaphragm and center disk off the opposite end.
[Fig.5.6]
▪Be careful not to scratch or score the center rod.
5.2 Inspection
▪Diaphragm
If the diaphragm is worn out or damaged, replace it.
New replace just one diaphragm.
Guideline of diaphragm life
NDP-5
PTFE 30,000,000 cycle
CR, NBR, PTFE 10,000,000 cycle
NDP-15
TPEE, TPO 15,000,000 cycle
▪Center rod [Fig.5.7]
Measure the diameter, and if it is outside the usable range,
replace the rod.
Usable range of center rod
NDP-5 Ø9.95 ~Ø10.0 mm
NDP-15 Ø13.96 ~Ø14.0 mm

7
5.3 Installation
■B□H, B□S, FPH, FPS types
For installation, see [Exploded View] on the separate sheet and install in the reverse order of disassembly.
▪Apply grease to the center rod, and insert it into the main
body.
▪Keep the convex side to the outside.
▪Tighten the center disk using the open-end wrenches for the
NDP-15FP□, BPS. (No coned disk springs and nuts are
needed.)
▪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 center rod and out chamber
Center rod Out chamber
NDP-5 7.5 N•m
NDP-15 14 N•m 12 N•m
<NOTE>
▪Make sure there is no dust on the seal surface in order to
prevent seal damaged.
▪Tighten the bolts that balance should be equal from both
side on diagonal line with even torque.
■B□C, B□N, B□T, FPC, FPN, F□T types
For installation, see [Exploded View] on the separate sheet and install in the reverse order of disassembly.
▪Apply grease to the center rod, and insert it into the main
body.
▪Keep the marking “LIQUID” to liquid end for CR, NBR
diaphragms.
▪Keep the convex side to the outside for PTFE diaphragm.
Install the O ring (cf. Fig.5.9).
▪Tighten the center disk using the open-end wrenches.
▪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 center rod and out chamber
Center rod Out chamber
NDP-5 7.5 N•m
NDP-15 14 N•m 12 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 that balance should be equal from both
side on diagonal line with even torque.

8
6.Pilot valve Assembly, Guide and Bushing
6.1 Removal
■NDP-5
▪Remove the diaphragm and center rod etc.(see [5.1
Removal] on P.5)
▪Remove the main body. [Fig.6.1]
▪Draw out the pilot valve assembly. [Fig.6.1]
▪Remove the packing and bushing. [Fig.6.1]
■NDP-15
▪Remove the diaphragm and center rod etc.(see [5.1
Removal]onP.5)
▪Remove the body B. [Fig.6.2]
▪Draw out the pilot valve assembly. [Fig.6.2]
▪Remove the packing, bushing and guide. [Fig.6.2]
6.2 Inspection
▪Bushing (NDP-5) [Fig.6.3]
Measure the inside diameter, and if it is outside the usable
range, replace the bushing.
Usable range of bushing
Ø10.1 ~ Ø 10.3 mm
▪Guide ( NDP-15 ) [Fig.6.4]
Measure the inside diameter, and if it is outside the usable
range, replace the guide.
Usable range of guide
Ø14.1 ~ Ø 14.2 mm
▪O ring, Packing
If the O ring is worn out or cracked, replace it.
▪Pilot valve assembly
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.
The correct direction of the V packing
<NOTE>
▪Make sure there is no dust on the seal surface and the
sealisnotdamaged.
▪Apply grease to packing.
▪The open side of the V faces toward the diaphragm (air
chamber).
Ｆig.6.2

9
7. C spool valve assembly and Sleeve assembly
7.1 Removal
▪Remove the cap using the cap and disk remover (special tool:
Part No. 771132). [Fig.7.1]
▪Draw out the C spool valve assembly using the plyer, and
remove the seal ring from the C spool valve assembly.
[Fig.7.2]
▪Remove the sleeve using the sleeve remover (special tool:
Part number 713148). [Fig.7.3]
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
NDP-5 1.40 ~ 1.48 mm
NDP-15 1.82 ~ 1.90 mm
▪Sleeve Assembly [Fig.7.5]
Measure the inside diameter, and if it is outside the usable
range, replace the sleeve assembly.
Usable range of Sleeve
NDP-5 Ø9.5 ~ Ø 9.55 mm
NDP-15 Ø15.8 ~ Ø 15.85 mm
▪O ring
If the O ring is worn out or cracked, replace it.
<NOTE>
▪C Spool Valve Assembly and Sleeve Assembly must be
Replaced 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.
<NOTE>
▪Make sure there is no dust on the seal surface and it is not
damaged.

10
8. Retightening of Tie rods
▪The torque should be applied on the occasion of
(1) Right before the pump to use.
(2)Thereareanyleaksofmaterialondailyinspectinga
pump.
Retainer bolts from the
out chamber
Retainer bolts from the
manifold
NDP-5 FPT, FVT, FDT
7.5 N•m 7.5 N•m
NDP-15 FP□, FVT, FDT
12 N•m 12 N•m
<NOTE>
▪Tighten the bolts that balance should be equal from both side on diagonal line with even torque.
▪Retighten the Out chamber and then the manifold in this order. [Fig.8.1]

Manufactured by
YAMADA CORPORATION
INTERNATIONAL DEPARTMENT
No.1-3, 1-Chome, Minami- Magome, Ohta-Ku, Tokyo, 143-8504, Japan
PHONE : [phone]
FAX : [phone]
201710 NDP183M