IMTMA-ACE MICROMATIC

Productivity championship

awards 2019

20th and 21th August 2019

Bengaluru

Bharat Heavy Electricals Ltd

2

2015-16 Turn over Rs. 800 Crores

Over 30,000 of Valves were manufactured and

supplied during the year.

• High Rework Rate due to Back Seat

• Leak High Rejection Rate due to Seat Crack & Stem Collar Breakage

• High Process cost and Production Cycle Time due to Body-Yoke Welding.

Hand & Motor

Operated

Carbon Steel &

Alloy Steel

2015-16 (~26K)

Bypass Valve

Pressure Relieving Valve

Main Valve

Start

Raw material

Machining-

Valve body

Pre-Heating

Seat Welding

Post Heating

Final

Machining-

valve body

Inspection

Pre-heating

Root welding

Arc Welding

Stress

Relieving

Penetration

Removing

OK

No

t O

K

Radiographic

Inspection

LP Inspection

Shot Blasting Phosphating

Spot facing

Assembling

Hydrotesting

Final

Inspection

Handover to

User

End

Re-

Wo

rk

No

t O

K

Re-

Wo

rk

OK

22

Activities

Re-

Wo

rkMachining-

yokeM

achin

ing

Lapping

Parting

Re-Work

Shell TestSeat Test Backseat Test

Valves is in fully

closed condition

5% of the Valves

Tested Annually

fails this Test

As per the

Manufacturer Test

Procedure.

Valves is in partial

open Condition

There should be no

leak from the

Body-Yoke

Assembly or the

Packings

Valve is in fully

opened condition,

and seated against

the backseat.

No leak should be

there from the

Packing region

30% of the Valves

Tested Annually

fails this Test

Body Seat

Rejection

Body Yoke

Welding Rejection

Due to repeated heat treatment, during

Body – Yoke welding. The seat cracks.

This seat crack, calls for rejecting Body or

Yoke

After the Seat Leak, LPI is done

again, which shows Seat Crack in

some of the Cases

Since Conventional Welding is involved,

defects in welding are unavoidable

13% of Valves manufactured annually get

rejected due to this

1.Cycle Time

2.Material Handling

3.Rework Rate

4.Cost of Valve

5.Operator Fatigue

1.Productivity

2.Safety

3.Customer Satisfaction

Wastage of

Manpower and

Resources

Sl.No Problem No of Valves

1 Backseat Leak 2129

2 Seat Leak 350

3 Center Out Problem 253

4 Improper Machining 127

5 Yoke Thread Problem 59

Total 2918

RT & UT FAILURE DATA - 2015-16

MONTH Size-1/2" Size-1"Size-1

1/2"Size-2"

TOTAL

(Nos)

JUNE 5 10 0 1 16

JULY 1 0 1 3 5

AUGUST 0 0 0 0 0

SEPTEMBER 3 0 15 16 34

OCTOBER 9 19 1 0 29

NOVEMBER 2 1 0 0 3

DECEMBER 7 38 2 0 47

JANUARY 8 18 0 2 28

FEBRUARY 0 59 2 24 85

9 MONTH 247

1 MONTH 25

PER ANNUM 330

PRODUCTION 26613

Percentage of

Rejection =13%

Percentage of

Rework =11%

1. Disc – Disc Retainer – Inside of Packing Ring

2. Disc Retainer – Packing Bush – Inside of Packing Ring

3. Body – Outside of Packing Bush – Outside of Packing Ring

Disc

Disc Retainer

Packing Bush

Retainer

Packing

Ring

Return to New

Order Cost of Process Rate Cum Rate % Cum %

A Welding and Inspection 588 588 28.52 28.52

B Yoke 295 883 14.31 42.82

C Body Machining 290 1173 14.06 56.89

D Body 251 1424 12.17 69.06

E Stem 200 1624 9.7 78.76

F Yoke Machining 135 1759 6.55 85.31

G Packing Bush, Retainer, Support 120 1879 5.82 91.13

H Dies & Retainer 100 1979 4.85 95.97

I Stud 58 2037 2.81 98.79

J Nut 25 2062 1.21 100

28.52

42.82

56.89

69.06

78.76

85.31

91.1395.97

98.79 100

0

10

20

30

40

50

60

70

80

90

100

0

500

1000

1500

2000

A B C D E F G H I J

CU

M %

VA

LV

E C

OM

PO

NE

NT

RA

TE

Cost of valve-1/2” carbon steel valve

Total : ₹ 2,022

RT Failure

Penetration

Re-work

Seat Crack Rejection

Cost of Valve

• Welded Joint between Yoke and Body replaced by a screwed joint

• Stem integrated Tapered Backseat introduced.

20th July 2016 31st March 2017

Project Duration

Existing New

Return to Existing

1. Disc – Disc Retainer – Backseat - Inside of Packing Ring

2. Disc – Backseat Inside of Packing Ring

3. Body - Bonnet

Bonnet

AFTERBEFOREInternal

Treading

Leg provides extra strength

Bonnet Yoke

Internal

Treading

External

Treading

Threaded Body

Connecting Bonnet

Threaded Yoke

Retainer ring Stopper RingPacking bush

Copper Washer provided in

the Matching AreaFlexibility caused the

problem

Lapping and

Leakage

elimination

Screwed yoke:•No Welding•Interchangeability•Low cost•Less production time •No rework/rejection•Easy serviceable

Screwed bonnet:•No Power guns•Faster assembly•No defect•Easy serviceable

Forging body:•No welding•Different material•More strength

Spiral wound gasket:•No shell leakage•Easy replacement•Withstands<550 ®C•Easy serviceable at site

Taper feature in stem:•No collar cut at site•No load for disc•No customer complaint•Excess strength•No lapping/grinding

Threading:•All threads are metric•More Strength•No thread damage

Before

YOKE ACTS AS A PRESSURE PART

Carbon

Steel

Yoke

and

Body

Alloy

Steel

Yoke

and

Body

BONNET ACTS AS A PRESSURE PART

After

Carbon

Steel

Yoke for

Alloy

Steel

Body

₹ 251

₹ 295

₹ 588

₹ 36

₹ 37

₹ 290

₹ 135

₹ 7

₹ 58

₹ 25

₹ 200

₹ 100

Body

Yoke

Welding & Inspection

Retainer

Packing Bush

Body Machining

Yoke Machining

Stopper Ring

Stud

Nut

Stem

Disc & retainer

Total : ₹ 1,434

Bonnet Rs.80

28.52

42.82

56.89

69.06

78.76

85.31

91.1395.97

98.79 100

0

10

20

30

40

50

60

70

80

90

100

0

500

1000

1500

2000

A B C D E F G H I JC

UM

%

VA

LV

E C

OM

PO

NE

NT

RA

TE

Cost of valve

14.31

28.37

40.54

50.24

56.79

62.6

67.4670.27 71.49

0

10

20

30

40

50

60

70

80

90

100

0

200

400

600

800

1000

1200

1400

1600

1800

2000

B C D E F G H I J

Revised Cost of Valve

Cost of valve reduced

upto 29%

Start

Raw material

Machining-

Valve body

Pre-Heating

Seat Welding

Post Heating

Final

Machining-

valve body

Inspection

Pre-heating

Root welding

Arc Welding

Stress

Relieving

Penetration

Removing

OK

No

t O

K

Radiographi

c Inspection

LP Inspection

Shot Blasting Phosphating

Spot facing

Assembling

Hydrotesting

Final

Inspection

Handover to

User

End

Re-

Wo

rk

No

t O

K

Re-

Wo

rk

OK

14

Activities

Re-

Wo

rkMachining-

yokeM

achin

ing

Lapping

Parting

Re-Work

8 Activities

are

eliminated

Financial gain due to manufacturing of screwed type

valve manufacturing/annum

Sl.No Description of costing involved Amount (Rs.)

1 REJECTION COST (PDO) Rs.11,94,630

2 COST SAVING BY MATERIAL REDUCTION Rs.1,79,13,034

3 COST SAVING BY MATERIAL SUBSTITUTION Rs.49,73,464

4 ELETRODE COST FOR REWORK DUE TO RT FAILURE Rs.6,13,665

5 FURNACE COST Rs.11,80,940

6 REWORK COST Rs.35, 87,079

Total loss/annum Rs.6,32,05,514

Electrical energy savings:

25035 kWh/ year

Man hour savings:

89005 hrs/ year

Machining of the

New Body Internals

The approximate concentration of gases during

welding by stick electrode:

Gas SO2 CO CO2

Quantity

(mg/m3)2.62 17.2 5760

The concentration of elements in welding fume

Elements Mn P Al Ni

Quantity

(mg/m3)2.5 2.3 8.5 0.07

7 Million worldwide died in 2012

Fumes and Gases are produced as Air Pollutants

Welding fume is classified as

potentially carcinogenic to

humans

Gases produced : Ozone, Nitrous Gases, Carbon Monoxide, Phosphine,

Phosgene etc.

Irritation of the eyes,

nose, and chest

Coughing Shortness of breath Bronchitis Nausea / Vomiting

Loss of appetite

Cramps

Fluid in the lungs (Edema)

Inflammation of the

lungs

(Pneumonitis)

Chronic lung problems

Bronchitis, Pneumonia,

Asthma, Emphysema,

Silicosis, Siderosis,

Lung Cancer Cancer of Larynx Cancer of Urinary tract

Parkinson’s Disease Skin Disease Kidney Damage Heart Disease

PATENT NO:

201731010196