Muktiadi Rahardjo of Shell has more advice to valve vendors
In the last Valve Insights we summarized a Valve World interview of Muktiadi
Rahardjo. He is the valve and sealing specialist at the Shell Pernis
refinery and based on this experience recommends better communication relative
to valve issues. Bob Mcilvaine
asked Adi some more questions and we received his quick and detailed response.
Bob: We have been reporting on
severe service valves. How do you define this term?
Adi: “Valves for severe service application are any valves that should sustain
or exceed an agreed period of lifetime in a super specific harsh environment and
shall perform within agreed/tolerable measurable boundaries e.g. leakage rate,
operable, speed of movement.”
Bob: In the previous interview last you referenced the need to better understand
the zero leakage concept. Can you
provide an example?
Adi: It is interesting that many of the vendors claim to have a Tight Shut Off
valve with Zero leakage. This may be right if the point of view was during
in-house testing using hot (clean) gas/air and or water after hundreds to
thousands of cycles. But I have to emphasize that the operational condition is
way different either for treated or untreated products. Also measuring bubbles
on the downstream side of the valve is either impossible if not hard due to
volume or other parameters.
TSO Metal to Metal valve falls into Leakage rate Class B as per ISO 5208, which
allows several bubbles per minute. Simply claiming “Zero bubble” is misleading
to the end user and kills the spirit of improvement by other manufacturers.
Bob: Can you elaborate on this
example?
Adi: “A tight shut off ball valve in particular will have a super tight gap
between its sealing components. At the wrong conditions, it may be prone to
differential thermal expansion rates for components in contact with each other.
I have experience with one of the suppliers claiming no bubbles in a SIL 2
classification. The ball valve was unable to move when required due to the fact
that the ball heated up more than the body which remained colder due to the heat
loss.
End users in general and especially for complex refineries have unique know how
of materials’ and valve type selection. For instance Stellite Hard facing is
more prone to problems in amine service. PTFE is prone to swell in the presence
of Ethylene Oxide (EO), Fossil
based soft goods in addition to Non-exempted material are prone exothermic
reaction for LOX (Liquid Oxygen) and GOX (Gaseous Oxygen) service. These are
just some examples of the materials experience accumulated by large refineries.
Bob: Are there other examples
relative to the need for information exchange?
Adi: Many manufacturers try to re-design the Rising Stem Ball Valve. Most fail,
but some are indeed succeeding. In my humble opinion, the differences are minor.
It is just some tweaking on how to do maintenance differently. This being the
case it is unwise for the installation and operation manual to specify that
maintenance without supervision will breach the warrantee.
Bob: What are the main
drivers affecting your valve decisions?
Adi: In general end users are
driven by two main things:
Regulations e.g. Fugitive
Emission classification, HF Alkylation, UOP Phillips, etc. The future challenge
is: can a valve be dry and clean enough (without fossil based soft goods and
lubricant) to meet the standard and still have a competitive price. Also can it
perform within Fugitive Emission restrictions for the next 25 years? Please note
that dry sealing elements will cause higher friction and is prone to galling of
components. Also 25 years is standard valve lifetime in a refinery.
Suitable lifetime and delivery time of valves or its spare parts.
The performance has to be sufficient to coincide with the expected down time in
conjunction with other components e.g. pump, compressor, vessel, etc.
Note: We do allow some leakage rate for
most valves. In order to make it zero leakage, normally we use double barrier
after the valve. End users have the need to minimize downtime. So failures
by valve manufacturers relative to support and maintenance should not be
allowed.
If a valve fails spare parts and personnel who can repair it should be available
within 1 to 3 days. 10 years ago acceptable delivery time was 12 weeks, it is
now moving towards 3-4 weeks or even earlier. That is why I advise well-known
manufacturers to treat all customers as special. They should broaden their
manufacturing network across the globe in order to achieve acceptable delivery
time of spare parts and also spread their (basic) knowledge among end users.
Consensus must be reached between End user (Principal) and manufacturer stating
that SSV will sustain xx years; within xxx threshold measurement level (leakage,
speed, etc.); under proper operational workmanship and agreed process
conditions.
Claims of “the best valves in the world, zero leakage and maintenance free” are
suspect. It is like a well-known car manufacturer claiming to be the fastest
without any chances of crashing. It
is detrimental to the industry if unsubstantiated and unachievable claims are
made.
This is not to say that progress toward this end cannot be made. But it requires
good synergy between the manufacturer and end user, starting from the design
phase and into operation (3-5 years until the warranty is void). My approach
would be to always create a double jeopardy scenario. The valve eventually will
fail, and another back up valve normally located downstream side should bear the
load of the failing valve until rectification is completed.”
Ross Waters weighs in on the zero leakage and need for a SSV definition
“I
think the basic topic is still centred on Severe Service Valves and their
definition. In Adi’s questioning, I too wonder why we are still using valve
technologies that were invented in the industrial revolution. There is no valid
reason to continue to use some of these basic valve types. Oil Companies
including Shell continue to keep manufacturers in business by buying and using
these products. It’s time to retire them.
Leakage for isolation valves is a performance based output. Not all valve types
can perform the same way, either initially or over their required life cycle.
The mystery is that the industry does not have a cohesive and effective way to
provide this performance. We confuse factory tests with the needs of the valve
in its application. Currently CGIS is conducting slurry cycle tests to obtain
objective data on the number of dynamic cycles a slurry isolation can reasonably
be expected to perform at a determined or maximum leakage rate.
In response to Bob McIlvaine’s suggestion that he organize a webinar with Adi,
myself and others interested in the subject I submit the following topics for
discussion:
1)
What is a severe service valve?
2)
Is zero leakage isolation possible?
3)
What is the minimum information required to properly select a severe service
valve?
4)
What special information is required to properly select a severe service valve?
5)
How valid are factory seat tests when compared to actual application
requirements?
6)
What are the advantages of separating your population of valves into Severe
Service and General Purpose?
7)
What valve types need to be mothballed?
New Choke Valve Initiative Decision Guide and Webinar
McIlvaine is compiling a continually updated Decision Guide for operators of
choke valves used in oil and gas and other industries for fluid control.
Contaminants such as sand integrated into varying mixtures of water, oil,
methane and other gases provide both operational and maintenance challenges. The
guide will identify the major applications and then the performance of various
designs and various materials for specific conditions. The guide will be the
basis of a recorded discussion to be conducted in early Fall 2016.
The guide will be offered free of cost to any end user.
It will also be published in Industrial Valves: World Markets and
Strategies. The wisdom of the
industry is sought in order to make this guide the best it can be.
Input is welcomed from any and all sources. White papers, articles and
other data to further the discussion would be most helpful. The background
information and part of the analysis has been prepared and is displayed at:
Choke Valve
Decision Guide.
For more information contact Bob McIlvaine at
rmcilvaine@mcilvainecompany.com
847-784-0012 ext. 112.
Organization of Webinars and Molecular Sieve Switching Valve Decision Guide
Decision Guides on choke valves and molecular sieve switching valves are just
two of many planned guides relative to severe service valves.
These guides will be the basis of webinars to be conducted this fall.
McIlvaine has prepared a number of Decision Guides and has conducted more
than 1000 webinars most of which have been recorded.
The molecular sieve switching valve guide will be an extension of the
following article published by McIlvaine.
Severe
Service Valve Technologies and Markets.
To see the schedule, click on:
Hot
Topic Hour Schedule and Recordings
Severe Service Valve Sales to the Chemical Industry will be just under $4
Billion in 2017
Severe service valves are required for 56 percent of all the valve applications
in the chemical industry. The definition of severe service includes valves
which are subject to abrasion, corrosion, unusual pressures, or must be designed
to meet stringent safety, sanitation, or contamination requirements.
Severe service valves are required for 75 percent of the process applications.
Since the process segment accounts for 63 percent of all the valves sold to the
chemical industry, the process severe service valves account for 42 percent of
all the valves sold to the industry.
Water used for cooling requires virtually no use of severe service valves.
Only 30 percent of the water intake valves are in the severe service category.
About half the wastewater valves are designed for severe service. These
are valves handling the slurry.
In 2017, the sales of severe service valves for processes will be just under $3
billion with the balance of $1 billion in the other three categories.
The percentages are based on revenues rather than amount of flow or the number
of valve units. While severe service valves will account for 56 percent of
the revenue, they will account for less than 30 percent of the flow and 20
percent of the unit sales.
Details on these forecasts are included in N028
Industrial Valves: World Market
Decision Guides on severe service valve options are already available for
coal-fired power, gas turbine combined cycle power plants, nuclear plants and
molecular sieve switching in gas treatment.
For more information contact Bob McIlvaine 847-784-0012 ext. 112
rmcilvaine@mcilvainecompany.com.
Bob McIlvaine
President
847-784-0012 ext. 112
rmcilvaine@mcilvainecompany.com
www.mcilvainecompany.com