This document discusses pitting and crevice corrosion issues with various metal alloys used in tubing. It provides examples of pitting and crevice corrosion occurring in duplex materials, 2507 material, and 316 stainless steel tubing after only a few years of use. The document recommends using super duplex alloys or Tungum alloy to avoid these corrosion issues. It also provides information on the benefits of Tungum alloy for tubing applications, including its resistance to pitting and crevice corrosion over long periods of use in marine environments.

2. Pitting Corrosion

3. Pitting & Crevice Corrosion
Grinding debris from
work carried above a
tube run that has
initiated Pitting
Corrosion on Duplex
material..

4. Pitting & Crevice Corrosion
Note the Crevice
Corrosion on this
2507 material at the
back of the fitting &
on the tube.

5. Crevice Corrosion Under Clamps

6. Pitting & Crevice Corrosion
316 Metal on metal –
not
a good idea. Note the
2 points of Crevice
Corrosion where the
clamp makes contact
with the tube

7. 316 Stainless Steel Time to
Failure
“316 Stainless tube failed after 2 years on a
new Tug Boat” Malcolm Parratt, New Build
Superintendent, Swire Offshore.
“The 316 Stainless Steel tube failed on the
Bonga FPSO after 18 months in service”
Yemi Okeremi, Senior corrosion Engineer at
Shell.

8. 316 Stainless Steel Time to
Failure
“In the past 3 years alone, dozens of in-service tubing failures in
small-bore 316L SS tubing have been reported on most BP-
operated GoM deep-water installations. The vast majority of these
incidents are attributed to external corrosion, the cause of which is
due to the susceptibility of 300-series austenitic stainless steels to
crevice and pitting corrosion in marine atmospheric environments.
Other BP locations (e.g., North Sea, Trinidad), major oil and gas
producers, and other sectors such as the NASA and the military
have had similar historical and recent experience with chronic
external corrosion of Type 316L SS tubing.
This problem not only results in service disruptions and
increasingly expensive maintenance and repair, but poses
potentially significant risks to health, safety, and the environment
if not effectively mitigated and/or prevented.”
Ardjan Kopliku – BP Corrosion Lead -GoM

9. Pitting & Crevice Corrosion Super
Duplex Alloys
Crevice Corrosion on
2507 tubing
accelerated by the
316 clamp “fingers”
separating the tube.

10. Crevice Corrosion
Despite more than 10 years marine exposure on a Shell semi submersible
support vessel the exposed surface of a section of Tungum Alloy Tube
remains clear of corrosion.
The Stainless steel Section from a Southern North Sea gas platform in the
Leman field shows crevice corrosion after barely 4 years in the same
environment.
Crevice Corrosion
on 316 St.Steel
under the clamps.

11. Total Lifetime Capital Cost based
on 30 Years

12. Oil & Gas- HP control lines
<5,000 psi
Tungum tube runs
(gold colour) showing
standard working
practices for
clamping & bend
radius’s

13. Oil & Gas- Safety Shut Down Conduit
Tungum tube runs used as a
corrosion resisting conduit for wire
rope
90°
Pulleys

14. Oil & Gas- Clamping Arrangements
Tungum tube runs (gold colour) showing standard working practices for
using St.Steel twin ferule fittings & 3x Dia. bend radius’s . However, not a
good idea to have 2 tube runs tight side by side. Leave a 5mm minimum
gap where possible.

15. Oil & Gas- HP Lines Twin Ferrule Fittings
Tungum tube runs (gold
colour) showing standard
working practices for using
St.Steel twin ferule fittings &
3x Dia. bend radius’s

16. Dive Systems – Tungum for O₂ Service

17. Oxygen Compatible Systems – Hyperbaric
Chamber

18. Military Fighting Vehicles, Hydraulic Lines

19. Transport – Brake Line Systems

20. Typical End Users & Specifiers

21. Tungum Protective Oxide Layer
Tungum’s protective
oxide layer polished
back to reveal that
no crevice corrosion
has occurred under
the pipe clamp.

22. Tungum Protective Oxide Layer
Tungum tube used
for Temperature
Safety Element
(TSE) loops in
service for 15 years.
Note the green
verdigris oxide
layer, on the tube.
This is to be
expected after this
period of time and
is part of the tubes
protective system.

23. Tungum Protective Oxide Layer
Tungum tube
showing the green
verdigris
oxide layer after 15
years in service with
no galvanic
corrosion issues
with the St.Steel
fittings into the
bulkhead.

24.  Hydraulic lines <5,000 psi
 Pneumatic lines <5,000 psi
 TSE Loops
 Sea Water – Flow rate < 4-5 mtr per/sec
 Pressure sensing lines
 Potable water lines
 Grey & black water
 Chemical injection lines – Caution, solution compatibility
 Diesel / fuel lines
 Oxygen lines
 Conduit tubing- Emergency shut down systems
Important note – Avoid applications with Acetylene
Ammonia & Mercury
Applications in Oil & Gas Non-Process

25.  Excellent lifetime cost compared to other tubing options
 No recorded failures of Tungum tube when correctly
used and installed
 Compatible and approved with all industry recognised
tube fittings
 Quicker installation times - can be as little as 75% of the
time compared to Super Duplex or Austenitic St.Steels
 Reduced system down times due to its longer life
 Material of choice for Oxygen and hyperbaric systems
 Over 30 years of experience of real time Oil & Gas
applications
Key benefits

26. ISO9001:2008 Approval

27.  ASTM B706-00 Temper TF00 “Seamless Copper Alloy (UNS No.
C69100) Pipe and Tube”
 BS EN 12449-CW700R-R430 “Copper and Copper Alloys-
Seamless, Round Tubes for General Purposes”
 ASTM G124-10 “Determining the Combustion Behavior of Metallic
Materials in Oxygen-Enriched Atmospheres”
 ASME B31.1 and B31.3
 USCG – United States Coast Guard
 Identified as ALLOY CZ127
 In-house specification TCL100
 Ministry of Defence specifications:
 Aviation: DTD5019 (for high pressure systems)
DTD253A (for low pressure systems)
 Navy: NES749 part 3
 Army: AFS4000
Specifications

28. Chemical Composition
Element Min % Max%
Copper 81.00 84.00
Aluminium 0.70 1.20
Nickel 0.80 1.40
Silicon 0.80 1.30
Iron 0.25
Lead 0.05
Tin 0.10
Manganese 0.10
Total Other 0.50
Zinc The Remainder

29. Physical Properties
Mean Ultimate Tensile Strength 480 N/mm²
(31.07 tons per Sq. in.)
Mean 0.2% Proof Stress 240 N/mm²
(15.54 tons per Sq. in.)
Design Stress at 4:1 Safety Factor 107.5 N/mm²
(6.96 tons per Sq. in.)
Hardness 140 HV5 max.
Elongation (Average) 45 Per Cent
Magnetic Permeability 1.0015µ Max.
Thermal Conductivity at 300 K 1.0W/cm K.
Weight 8.52 x 10 kg/mm³
(0.308 lbs per cu.in.)

30. Typical material test cert

31.  Family owned UK Limited Company
 Established in 1933
 World wide distributor network
 World wide approvals and
certifications
Tungum Limited

32. Tungum Worldwide
 PAC Stainless USA www.pacstainlessltd.com
 Global Hydraulic Singapore www.globalhydraulics.com.sg
 Stauff –Korea Korea www.stauff.com
 Items AB Sweden www.itemsab.com
 Fernandez Jove S.A. Spain www.fernandezjove.com
 Petrotech LLC Middle East www.petrotech.ae
 Hydrasun Ltd Scotland, www.hydrasun.com
Netherlands
& Caspian Sea countries.