appears that previous posts have addressed the situation well - check to verify material as it does not appear to be PTFE - I have seen brittle fractures similar to this in PVDF lined pipe and fittings - PP lined components I suspect would be similar - PFA or PTFE fractures such as this I have not seen.
easy check is what Karin has recommended, put in water if it floats chances it is PP are good - if it sinks I would suspect it to be PVDF.
do you have data on the original manufacturer of the fitting (unfortunately many are supplied by a distributor and not well traceable to the original mfg...).
the pictures sent are not all that clear for determination of liner material - traditionally the liner color indicates the material; black = PVDF, orange = PP, white or translucent = PTFE/PFA - I have seen instances where the natural color of PVDF was supplied
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Dale Keeler
Non Metals TSTL
Dow
lake jackson TX
9792385650
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Original Message:
Sent: 06-17-2020 10:47 AM
From: Pradip Khaladkar
Subject: PTFE failure of Cross Joint
If it is PTFE (this can be confirmed by analytical tests) then one possibility is an extremely poor sintering. I did come across a case of poorly sintered lined pipe spool which looked like this. Also the lining thickness looks to be too high. I can't be sure from the picture.
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Pradip Khaladkar
Fellow and Associate Director
MTI
DE
302 245 8426
Original Message:
Sent: 06-17-2020 08:43 AM
From: Bernhard Rijpkema
Subject: PTFE failure of Cross Joint
Hi Aamir,
It will certainly not be PTFE. One-piece crosses can not be made with PTFE, but are normally offerered with transfer moulded PFA. The PTFE lined crosses are two-piece items.
But apart from that, also PFA should not show this behavior in your conditions. We use PTFE and PFA lined parts in exactly the same conditions to support this.
My first impression was also that this might be made of PP lined steel, an option offered by most PTFE lined pipe suppliers. PP would show a more brittle behavior and also more interaction with the chlorine in the sulfuric acid.
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Bernhard Rijpkema
Manager Materials Technology
Nouryon
Original Message:
Sent: 06-17-2020 03:37 AM
From: Karin Jacobson
Subject: PTFE failure of Cross Joint
You can also just quickly check if the material floats. If it does it is most probably a polyolefin; PP or PE.
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Karin Jacobson
PDS Consulting
0735127103
Original Message:
Sent: 06-16-2020 12:15 PM
From: Ahmed Altaher
Subject: PTFE failure of Cross Joint
Aamir,
The sharp edge of the liner inside diameter indicates that the liner is injection molded and PTFE does not flow.
This liner looks to be polypropylene, a melt flow rate analysis can provide data to help determine if the material is polypro.
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Ahmed Altaher
Chemours
Ingleside TX
361-776-6881
Original Message:
Sent: 06-15-2020 03:38 AM
From: AAMIR SADDIQ
Subject: PTFE failure of Cross Joint
Does anyone have experience such PTFE failure with in one year service period.
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It contains 60- 70%H2SO4 and has about temperature cycles from 15 to 30c. with moisture and some traces of cl2 from chlorine dryer column.
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AAMIR SADDIQ
STATIONARY ENGINEER
SABIC
JUBAIL
00966133574273
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