YAMADA NDP-40, NDP-50, NDP-80 Maintenance Manual

Doc. No. NDP 027M-39

MAINTENANCE MANUAL

YAMADA AIR-OPERATED DOUBLE DIAPHRAGM PUMP

NDP-40 series
NDP-50 series
NDP-80 series

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.

WARNING :

CAUTION

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.

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. 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

· PP wrench (sold separately) · Sleeve remover (sold separately)

Purpose: Removing the center disk Purpose: For removing sleeve

of BP_ and BV_ types

2.3 Misc.

· Assembly oil Turbine oil none addition class 1(equivalent ISO VG32 grade)

· Nuts M16

· Thread locker

· Grease Urea grease grade (NLGI) No. 2

X 1.5

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.

1

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]

2