YAMADA NDP-40 series User manual

MAINTENANCE MANUAL
YAMADA AIR-OPERATED DOUBLE DIAPHRAGM PUMP
NDP-40 series
NDP-50 series
NDP-80 series
Doc. No. NDP 027M-39

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-40 series,
NDP-50 series and NDP-80 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 and Valve seats
4.1 Removal
■BA_, BS_, BF_ types·····························································2
■NDP-40 BP_·BV_ type···························································3
■NDP-50 BP_·BV_, NDP-80 BP_ types ·······································4
4.2 Inspection ···········································································5
4.3 Installation···········································································5
5. Diaphragm and Center rod
5.1 Removal
■BA_, BS_, BF_ types·····························································6
■BP_, BV_ types····································································6
5.2 Inspection ···········································································7
5.3 Installation
■B_C, B_N, B_E, B_V, B_H, B_S types ·······································7
■B_T types ···········································································8
6. Throat bearing and Pilot valve
6.1 Removal ·············································································9
6.2 Inspection ···········································································9
6.3 Installation···········································································9
7. C Spool valve assembly
7.1 Removal ··········································································· 10
7.2 Inspection ········································································· 11
7.3 Installation········································································· 11
8. Retightening of Tie rods······················································ 12

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 13mm, 17mm, 19mm (except with the NDP-40 BP_, BV_),
24mm (BA_, BS_, BF_)
· Hexagonal box wrenches 5mm, 6mm
· Small crowbars 2 (B_C, B_N, B_E, B_V)
· Open-end wrenches 17mm (NDP-40 BP_, BV_), 19mm (BA_, BS_, BF_),
24mm (BA_, BS_, BF_)
· Plastic hammer
2.2 Special tools
· PPwrench(soldseparately) · Sleeve remover (sold separately)
Purpose: Removing the center disk Purpose:Forremovingsleeve
of BP_ and BV_ types
2.3 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
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 and Valve seats
4.1 Removal
■BA_, BS_, BF_ types
▪Remove the 6 (8 on the NDP-80) retainer bolts “1” from the out
manifold, and remove the out manifold. [Fig.4.1]
▪Remove the ball, valve seat and O ring. [Fig.4.2]
▪Remove the 6 (8 on the NDP-80) retainer bolts “2” from the in
manifold, and remove the in manifold. [Fig.4.1]
▪Remove the ball, valve seat and O ring. [Fig.4.3]

3
■NDP-40 BP_·BV_ type
▪Remove the 8 retainer bolts “1” from the out manifold, and
remove the out manifold. [Fig.4.4]
▪Remove the ball, valve seat and O ring. [Fig.4.5]
▪Remove the 8 retainer bolts “2” from the in manifold, and
remove the in manifold. [Fig.4.4]
▪Remove the ball, valve seat and O ring. [Fig.4.6]

4
■NDP-50 BP_·BV_, NDP-80 BP_ types
▪Remove the 6 (8 on the NDP-80) retainer bolts “1” from the out
manifold, and remove the protector and out manifold.
[Fig.4.7]
▪Remove the ball, valve guide (only NDP-80), valve seat and
O ring. [Fig.4.8]
▪Remove the 6 (8 on the NDP-80) retainer bolts “2” from the in
manifold, and remove the protector and in manifold. [Fig.4.7]
▪Remove the ball, valve guide (only NDP-80), valve seat and
O ring. [Fig.4.9]

5
4.2 Inspection
▪Ball [Fig.4.10]
Measure the outside diameter, and if it is outside the usable
range, replace the ball.
Usable range of ball
NDP-40 Sø1.772 ~ Sø2.028 in
{Sø45.0 ~ Sø51.5 mm}
NDP-50 Sø2.232 ~ Sø2.555 in
{Sø56.7 ~ Sø64.9 mm}
NDP-80 Sø3.189 ~ Sø3.650 in
{Sø81.0 ~ Sø92.7 mm}
▪Valve seat [Fig.4.11]
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_T
NDP-40 0.181 ~ 0.453 in
{4.6 ~ 11.5 mm} 0.067 ~ 0.165 in
{1.7 ~ 4.2 mm}
NDP-50 0.197 ~ 0.492 in
{5.0 ~ 12.5 mm}
NDP-80
▪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
BA_, BS_ BP_, BV_
NDP-40 18 ft-Ibf {25 N-m} 15 ft-Ibf {20 N-m}
NDP-50 18 ft-Ibf {25 N-m}
NDP-80
<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.4.12]
(NDP-50 BP_·BV_, NDP-80 BP_)

6
5. Diaphragm and Center rod
5.1 Removal
■BA_, BS_, BF_ types
▪Remove the ball and valve seat etc.(see [ 4.1 Removal BA_,
BS_, BF_ types])
▪Remove the 16 (24 on the NDP-80) 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 nut 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.
▪Remove the nut on the opposite side using the double nut.
[Fig.5.3]
▪Remove the coned disk spring, center disk and diaphragm.
■BP_, BV_ types
▪Remove the ball etc. (see [ 4.1 Removal BP_, BV _types]).
▪Remove the 8 (4 on the NDP-40) retainer bolts from the stand
body, and remove the stand body. [Fig.5.4]
▪Remove the 16 (24 on the NDP-80) retainer bolts from the out
chamber, and remove the out chamber. [Fig.5.5]

7
▪Remove the center disk from one side using the PP wrench
(special tool: Part No. 771868). [Fig.5.6]
▪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.5.9]
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
CR, NBR, EPDM 10,000,000 cycle
FKM 2,500,000 cycle
PTFE 3,000,000 cycle
TPEE, TPO 15,000,000 cycle
(When used with clean water at room temperature)
▪Center rod [Fig.5.8]
Measure the diameter, and if it is outside the usable range,
replace the rod.
Usable range of center rod
ø0.9815 ~ ø0.9843 in {ø24.93 ~ ø25.00 mm}
5.3 Installation
■B_C, B_N, B_E, B_V, B_H, B_S 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 (except with the NDP-80). (cf. Fig.5.9)
▪Keep the marking “OUTSIDE” to liquid end for CR, NBR, EPDM,
FKM diaphragms. Keep the convex side to the outside for TPEE,
TPO diaphragms.
▪Tighten the center disk using the PP wrench (special tool: Part
No.771868) for the BP_, BV_ types. Apply proper Thread locker
to the thread of center disk.
(No coned disk springs and nuts are needed.)
Tightening torque for center rod
BA_, BS_, BF_ 43 ft-Ibf {60 N-m}
BP_, BV_ 36 ft-Ibf {50 N-m}

8
▪Draw the center disk to one side (exclude B_H, B_S type
cf.Fig.5.9).
▪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 type) [Fig.5.10, 5.11]
▪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.
BA_, BS_, BF_ 29 ft-Ibf {40 N-m}
BP_, BV_ 26 ft-Ibf {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 of the air chamber using
a crowbar, etc.
▪Tighten the bolts gradually in a diagonal sequence with even
torque. (cf. Fig.5.12)
■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.5.13).
▪Put the O rings to both sides of the diaphragm. (cf. Fig.5.13)
▪Tighten the center disk using the PP wrench(special tool: Part
No. 771868) for the BPT, BVT type. Apply proper Thread locker
to the thread of center disk.
(No coned disk springs and nuts are needed.)
Tightening torque for center rod
BAT, BST, BFT 43 ft-Ibf {60 N-m}
BPT, BVT 36 ft-Ibf {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
BAT, BST, BFT 29 ft-Ibf {40 N-m}
BPT, BVT 26 ft-Ibf {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. (cf. Fig.5.14)
Fig.5.12
Fig.5.14

9
6. Throat bearing and Pilot valve
6.1 Removal
▪Remove the diaphragm and center rod (see [5.1 Removal]).
▪Remove the 12 retainer bolts from the air chamber, and remove
the air chamber. [Fig.6.1]
▪Draw out the pilot valve and valve seat. [Fig.6.2]
▪Draw out the throat bearing. [Fig.6.2]
▪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
ø0.9859 ~ ø0.9902 in {ø25.04~ ø25.15 mm}
▪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
15 ft-Ibf {20 N-m}
<NOTE>
▪Make sure there is no dust on the seal surface and the seal is
not damaged.
▪Apply grease to packing.

10
7. C spool valve assembly
7.1 Removal
▪Remove the out manifold (see [4.1 Removal]).
▪Remove the 6 retainer bolts from the valve body, and remove
the valve body. [Fig.7.1]
▪Remove the 8 cap A and cap B retainer bolts, and remove cap
A and cap B. [Fig.7.2]
▪Draw out the C spool valve assembly, and remove the seal ring
from the C spool valve assembly.
▪Remove the spring stopper. [Fig.7.3]
▪Remove the sleeve using the sleeve remover (special tool: Part
number 713180). [Fig.7.4]

11
7.2 Inspection
▪C Spool Valve Assembly
Seal ring [Fig.7.5]
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
0.1484 ~ 0.1516 in {3.77 ~ 3.85 mm}
▪Sleeve Assembly [Fig.7.6]
Measure the inside diameter, and if it is outside the usable
range, replace the c spool valve assembly.
Usable range of sleeve
ø1.305 ~ø1.313 in {ø33.15 ~ø33.35 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
8 ft-Ibf {10 N-m}
Tightening torque for valve body installation bolts
12 ft-Ibf {17 N-m}
<NOTE>
▪Make sure there is no dust on the seal surface and it is not
damaged.

12
Fig.8.2
8. Retightening of Tie rods
■Plastic type
▪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]
■Metal type
▪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.8.3]
▪Tighten the bolts in the order shown. [Fig.8.4]
Retain bolts for the
out chamber
Retain bolts for the
manifold
NDP-40.50.80 BP_ 26 ft-Ibf {35 N-m} 15 ft-Ibf {20 N-m}
NDP-40.50 BV_
Retain bolts for the
out chamber
Retain bolts for the
manifold
NDP-40.50.80
B_C, B_N
B_E, B_V
B_T, B_H
B_S
29 ft-Ibf {40 N-m} 18 ft-Ibf {25 N-m}
Fig.8.4

YAMADA AMERICA, INC
955 E. ALGONQUIN RD., ARLINGTON HEIGHTS, IL 60005, USA
PHONE: [phone] or 1-800-990-7867 (Toll Free) FAX : [phone]
www.yamadapump.com
Manufactured by:
YAMADA CORPORATION
InternationalDepartment
1-1-3 CHOME, MINAMI MAGOME, OHTA-KU, TOKYO, 143-8504, JAPAN
PHONE : [phone] FAX : [phone]
201807 NDP027M