ukstt masterclass · –dvs 2207-1 welding of thermoplastics ... –iso low force similar than dvs...

UKSTT Masterclass

UKSTT Masterclass

Keith Mole

International Business Manager.

McElroy Manufacturing.

Background.

• 1970s – E. Pearts and Co

• 1980s - Vulcathene. (GPS)

• 1990s – Fusion Group

• 2000s - McElroy.

• UKSTT; PIG; PE100+

Outline

• History. of HDPE.

• The Science and Maths. - Fusion Process Variables.

• Fusion Machine

• Fusion Standards

• Productivity Accessories

• Conclusions

History of HDPE Pipe

• 1930s DuPont

• World War II

• 1953 HDPE Ziegler and Holzkamp

• 1955 HDPE Pipe.

• 1963 Ziegler awarded the Nobel Prize for Chemistry.

• 1970s Pipe (drainage, gas and water).

• PP Institute.

Science and Maths.

Fusion Process Variables

Fusion Machine Fusion Standard Accessories

• Fusion Process Variables

Fusion Standard

• Understanding the Fusion Process

t3 t4

Time

t1 Initial bead-up time

t2 Heat soak time

t3 Heater plate removal time

t4 Time to achieve fusion jointing pressure

t5 Cooling time in the machine under pressure

t6 Cooling time in the machine without pressure

t2t1 t5 t6

Pre

ssu

re

Fusion Standard

• What we used in the past:

– DVS 2207-1 Welding of Thermoplastics

– ASTM F2620: Standard Practice for Heat Fusion Joining of Polyethylene Pipe and Fittings

• What we have now:

– ISO 21307: Butt fusion jointing procedures for polyethylene (PE) pipes and fittings

Fusion Standard

• DVS 2207-1 : Developed by the German Welding Society, commonly used and accepted in Europe and other countries around the world.

• This standard is known as Low Pressure standard since the Interfacial Pressure used is 22 psi (1,5 bar or 0,15Mpa)

Fusion Standard

• ASTM F2620: Developed by American Society for Testing and Materials commonly used and accepted in the USA and Canada (Its also the base of TR33 for PPI)

• This standard is known as High Pressure standard since the Interfacial Pressure used is 75 psi (5,17 bar or 0,52Mpa)

Fusion Standard

• ISO 21307: Developed by a group of HDPE industry experts considering standards used all around the world in order to unify concepts into an International Standard.

• It considers three different Fusion Methods:

– Single pressure and low fusion jointing pressure

– Dual pressure and low fusion jointing pressure

– Single pressure and high fusion jointing pressure

Comparisons

Single Low Force.

This is mostly used in Europe and uses a pressure considered to be Low in the

heating and cooling process.

ISO Dual Force is very much used in the UK Water industry. Following the Single Force pressures but with a drop down in pressure

during the cooling process

Single High Force

This has been taken from the USA ASTM Spec and heats and cools at pressure

considered to be High

Fusion Standard

• Current Situation:

– Former ASTM users following ISO Single pressure and high fusion jointing pressure (0,52MPa)

– Former DVS users still following it or changing to ISO Single pressure and low fusion jointing pressure (0,17 ± 0,02MPa)

– ISO Low Force similar than DVS

– Dual pressure and low fusion jointing pressure not used much

Fusion Standard

• Example 1: 450mm, DR 21, en = 21,4mm

Fusion Joining Cycle - ISO HF vs LF

--

14,18

31,12

-

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0 5 10 15 20 25 30 35

Time (min)

Inte

rfa

ce

Pre

ss

ure

(M

pa

)

HF LF

Fusion Standard

• Example 2: 900mm, DR 21 , en = 42,9mm


--

27,90

59,58

-

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0 10 20 30 40 50 60 70

Time (min)

Inte

rfa

ce

Pre

ss

ure

(M

pa

)

HF LF

Fusion Standard

• Example 3: 1600mm, DR 21 , en = 76,2mm


--

49,23

103,85

-

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0 20 40 60 80 100 120

Time (min)

Inte

rfa

ce

Pre

ss

ure

(M

pa

)

HF LF

Fusion Standard

• Understanding the difference HF vs. LF

– It is easy to understand and to probe the advantages of fusing with HF standard considering the shorter cooling time t5

– But is also easy to understand the productivity provided in t1: ,t2: ,t3: & t4 and the other steps in the whole fusion process when you use a fully hydraulic machine

So what are the issues.

• Poor quality machines or set up.

• Accessories

• Low cost machines

• Training.

• Joint Failures.

Set up.

• Represents a third effect that we need to consider in the productivity calculations for butt fusion of HDPE pipes

• They are optional tools that make the operation easier, providing better productivity, safety, comfort and more important, reducing costs

Understanding the McElroy Advantage

• ...

McElroy Others

Costs

• Do we want to change to match competitors price?

Cost

• Taking away the mobility...

Cost

• Taking away the hydraulic rollers...

Cost

• Removing the pivoting facer & heater...

Cost

• Taking away the hydraulic clamping...


• After stripping the McElroy machine of its features, you will need some additional equipment on site

• We want the Industry Standard to be high quality, productive and efficient

• We would rather keep improving and adding features and concentrating in teaching customer about The McElroy Advantage


• Showing the whole fusion process:

Clean Install Clamp Drag Face Align Heat Fuse

Cooling

Total Fusion Time – 54” HDPE DR 17

Understanding the McElroy AdvantageStandards and Machines Comparison

1600mm, DR33

160,5

196,1

66,5

51,5

0

50

100

150

200

250

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Tim

e (

min

)

HF LF HF + HYD HF+HYD+ACC

Clean Install Clamp Drag Face Align ReFace Heat Fuse Cooling Unclamp Move Next Joint

Conclusions

• It is possible to calculate productivity in the butt fusion process, using the formulas given by the fusion standard used

• The type of machine used can help to estimate the productivity that would be added, mainly due advantages of hydraulics functions involved

• Productivity accessories represent an additional advantage in decreasing times and costs during the fusion process

Conclusions

• Butt Fusion is a great process.

• Standards can stifle innovation.

• Accountants can cost you money.

• Do it right first time.

Questions – Comments

• ...

ukstt masterclass · –dvs 2207-1 welding of thermoplastics ... –iso low force similar than dvs...

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