ABPG member individuals or companies. - Brimstone STS tank. 10 Sulfur Collection Header Configuration ABPG Lessons Learned 2012 11 Flange to Sulfur Collection Header Detail Area of

1

ABPG Lessons Learned 2012

The information and data furnished in this presentation are provided in good faith for

general informational purposes. This material is not intended to replace good engineering judgment based upon site-specific data and circumstances. While the views expressed are generally held under consensus, they do not necessarily represent the specific views of ABPG member individuals or companies.

The only source of knowledge is experience. Albert Einstein

2

http://www.brainyquote.com/quotes/quotes/a/alberteins148778.html�


Asquith, Jim – Valero Energy Corporation Bela, Frank – Member Emeritus (formerly

Texaco, Shell) Buziuk, Frank – Member Emeritus

(formerly Chevron) Crockett, Steven – BP (US) Davis, Jay – Chevron Eguren, Ralph – BP (US) Hatcher, Nate – Member Emeritus

(formerly ConocoPhillips) Heeb, Dick – Marathon Petroleum

Company LLC Hittel, Shelley – semCAMS

Keller, Al – Phillips66 Kennedy, Bruce – Member Emeritus

(formerly Petro-Canada) Bellinger, Brandon – Flint Hills Resources Schendel, Ron – Consultant Smith, Conrad – DCP Midstream Stern, Lon – Member Emeritus (formerly

Shell Global Solutions) Tracy, Frank - Phillips66 Tunnell, Duke – Business Manager Way, Bill – EnCana Corporation Welch, Bart – Chevron Young, Mark – Suncor Energy

3


LLD-024 H2S Properties LLD-023 Sulfur Collection

Header Incident LLD-022 Piping Changes in

Active ARU LLD-021 Injury Report of Sulfur Burn LLD-020 Startup Lessons Learned LLD-019 Hot Standby Refractory Failure LLD-018 Legal Implications & 2011

LOPA Update LLD-017 Hythe Plant HAZOP & LOPA LLD-015 Burner Light-off Sequence

LLD-014 Sulfur Pit Corrosion LLD-013 Oxygen Line Fire LLD-012 Compabloc Lean/Rich Plate

Exchangers LLD-011 SCOT Catalyst Sulfiding -

Problems LLD-010 OSHA National Emphasis

Program (NEP) LLD-009 ARU LOPA LLD-008 SO2 Emission Spikes LLD-007 Fixed Valve Trays

LLD-006 TGU Booster Blower LLD-005 Rich Amine Emulsions LLD-004 Presulfided TGU Catalyst LLD-003 Stripped Water pH LLD-002 Rich Amine Flash Drum Alarms LLD-001 TGU Mercaptans 2012 Topics for Vail 2011 Vail Topics Covered 2010 Vail Topics Covered 2009 Vail Topics Covered

4


Question Id: LLD-022 Title: Piping Changes in Active ARU Background: A contract pipefitter crew of two was installing piping in an Amine Unit as part of a

project while the unit was live. The intent of their specific task was to route a new oily water blow-down pipe to a suitable tie-in location on the existing oily water sewer system.

This is normally accomplished by terminating a plain pipe end above an open funnel on the oily water sewer system. [The piping isometric incorrectly positioned the new pipe end above an unlabeled, blinded stub-up that protruded above grade.]

What Happened: The plain end of the new blow-down pipe was fitted with a flange to mate with the

flange on the stub-up pipe. The contract workers were exposed to H2S when they loosened the studs on the blind

flange of the stub-up pipe. [It was subsequently determined that the stub-up pipe was part of the live amine drain system.]

5

LLD-022 Piping Changes in Active ARU


How it Happened: Several opportunities to detect the drawing error were missed, the engineering quality check, pre-construction work preparation, the project field change process that added the flange to the new blow-down line the work permit that approved the removal of the in-situ blind.

Worker exposure to H2S was possible because the pipefitter crew was not wearing SCBA required for this task.

Why it Happened: The piping system designer mistakenly selected an incorrect tie-in point and the

subsequent engineering quality check failed to detect the error. A pre-construction walk-through of the task with an operations representative was not required by the project execution standards.

An information request was initiated when it was recognized that a flange was required to mate up with the blinded stub-up pipe. The individuals involved did not wait for the Engineering response to the information request and proceeded with the tie-in.

The permit field verification was performed by Operations and although there was uncertainty regarding the identity of the unlabeled tie-in point, operations approval was given to open the blinded live line without absolute confirmation.

Despite recognition of potential H2S exposure, the pipefitter crew was not required to, nor chose to, wear SCBA in accordance with standard procedure related to H2S.

Live piping systems were not properly identified.

6



Heightened Risk of Injury: Rather than immediately evacuating the area per procedure, the crew opted to stay and

retighten the studs to stop the leak. Lessons Learned: The engineering drawings had been issued with errors. Despite the fact that the crew,

supervision and the Operator all had doubts about the proposed tie-in location, work proceeded without getting clarification.

Field changes were made without following proper procedures. Piping had to be modified in order to connect to the wrong tie point. Although the project field change procedure was initiated, the work was done prior to receiving approval from Engineering.

A deviant condition existed in relation to H2S which states that workers should evacuate the area at first signs of H2S. Workers often do not evacuate at the first indication of a release of H2S. All workers need to understand protocol and evacuate when personnel badges or alarms go off.

Final Note – Personal Commitment to Safety: Commit to executing work with caution and thoroughness. Do not assume that all

documentation received is correct. When in doubt, check it out. Commit to treating deadly substances with respect and a high level of caution.

7


H2S Leak and Flame Incident ABPG LLD-023

8


Background SRU 150 LTPD built in 2005 at a USGC refinery using modular

construction Prior to the event, experiencing sporadic H2S detector alarms

near the collection pit Operator inspection revealed steam tracing to the eductor and

air intake was off ◦ Started steam to the tracing and to the eductor ◦ Not identified it at the time, but the air intake was plugged

The incident That night Operators observed “vapors and flame” coming

from the 2nd and 3rd collection header inlet "flanges" Flame was extinguished with steam ◦ The vapor space TI indicated rising temperature in the collection

header; confirming presence of an internal fire

9

LLD-023 Sulfur Collection Header H2S Leak


Not shown, but there is an air intake stack on one end of the vessel and an eductor on the opposite end. Sulfur is pumped from vessel to storage tank.

10

Sulfur Collection Header Configuration

ABPG Lessons Learned 2012 11

Flange to Sulfur Collection Header Detail

Area of H2S leak and fire



The plate flange on top of the collection header was not bolted in place (not immediately obvious since the flanges are under grating and insulated)

The design intent was to use the weight of the piping and flange to compress the gasket material (PTFE) and provide a seal and while allowing for thermal expansion movement of sulfur piping to the collection header

This design led to the “atmospheric” vessel becoming a pressure vessel when the eductor was off and the air intake was plugged

Inspection or replacement of the gasket requires significant piping disassembly

Design improvements have been ordered

12


ABPG LLD-0024


Experimental data has shown that for every 10 ppm H2S dissolved in sulfur, the unvented headspace will contain about 2,000 ppm H2S. Using this rule, the H2S in an unvented tank headspace containing un-degassed sulfur can exceed the LEL.

MIE for methane in air is 0.30 mJ (MIE)

To put these values in perspective, static discharge from a human body is about 15 mJ or more than 200 times the energy needed to ignite a H2S/air mixture & oxidation of 1 mg of FeS would produce ~8 J, far more energy than the spark ignition energy.

For an electrostatic charge to ignite a flammable gas mixture there must be a charging mechanism, a way to store or accumulate the charge, and discharge across a gap. Flowing liquid that is poor electrical conductor, such as molten sulfur, is a well known way to build up large static charge; therefore, good grounding and bonding is important.

A flammable air-H2S mixture will easily find an ignition source

ABPG LLD-021

Initial Incident Notification, Recordable Injury-Medical Treatment (Burns to forehead)

For More Information, please Contact: Plant manager

What Happened? During routine rounds in the Sulfur Recovery Unit (SRU), the IP had worked to get a non-operating steam trap functioning and was checking to make sure that all sulfur rundowns were flowing properly. When he opened the look box to observe the rundown, molten sulfur filled the look box and then suddenly sprayed out the top, hitting the IP in the forehead causing minor burns. He also received minor burns to the back right middle and ring fingers and a small spot on the palm below his left thumb.

Immediate Concerns:

•What can be done to minimize the potential of personnel getting splashed with hot sulfur?

Actions: • The IP reported to the control room where notifications were

made • The IP was taken to a local hospital for initial examination where

he was diagnosed with first degree burns • The IP was transported to the city Burn Center for further

evaluation. • The burn center excised (removed) the top layers of skin from

the burns on the fingers and palm. • Immediately implemented the requirement for a face shield and

heavy cotton gloves when exposure to sulfur or steam is possible.

Incident Date/Time: 01/03/2012 / 3:30 AM

Photo of Incident Area

This notice provides only initial incident information. After the investigation is completed a report will be completed in Traction and Lessons Learned will be communicated.

Re-enactment

Look boxes

LLD-021 Sulfur Burn Injury


Concerning the above incident--The procedure has now been modified to require wearing a face shield. I don’t know to what extent this is general industry practice.

1-6-12 Not aware of any requirement to wear face shields. However, we are relying more on the

inline sight glasses in the newer plants to avoid this exposure risk, and did not install look boxes in our latest design.

Bruce Scott used to tell the war story about an IP who had a full face shield on, but when the hot sulfur blew he turned his head and got some in his ear causing significant damage. His point was to make sure the entire head/neck area is covered.

The face shield policy was of course a necessary interim safeguard, but I am interested in the results of the root cause analysis. I suspect this particular hazard is somewhat site-specific. Most look box lids in my experience are not that tight, and perhaps it was so retrofitted in response to chronic downstream restrictions. If so, this is not the first time a look box overflowed, just the first time injury resulted.

I also question why first degree burns required removal of skin. Proper first aid would

be to immediately cool the affected area with water, then apply soap lather to facilitate sulfur removal.

17 LLD-021 Sulfur Burn Injury


1-9-12 Thanks for sharing. Too bad it takes a mandate to protect people from doing things like this.

This is the kind of input I would like to see more of. I realize they will be sanitized, but the more

we become aware of these incidents the more effective we can be in HAZOP / LOPAs and unit design.

Thanks for sharing. Even if we have been exposed to similar incidents, it is always good

to refresh the incident discussion topic list.

We have all probably been exposed to situations where it has been difficult to enforce PPE requirements. Many operators question the need for face shields and goggles. Or, someone without the appropriate PPE just wants to take a "quick peek" without having to go get the proper gear. One place I worked had what I considered to be a very good, operator- suggested, solution. They strategically located a number of oversized rural mailboxes throughout the unit for housing special PPE likely to be required in that area. We rarely had PPE violations.

1-17-12 I checked with one of our superintendents and his answer surprised me. The potential hazard

from a splash of liquid sulphur from our look boxes had been identified in our Hazard ID program. Because our operators brought it up, there is a very high percentage of operators who comply with the policy of using full face shields and special suits when checking these look boxes. Other precautions include standing to the side when loosening the lid. He further commented that if anyone was found to violate this safety precaution because they wanted a quick look, they would be subject to dismissal. Maybe that's another reason for the high rate of compliance.

18 LLD-021 Sulfur Burn Injury

SRU/TGU Startup Lessons Learned

ABPG LLD-020


General Advice New unit startup advice can be summarized as follows: Take nothing for granted. Allow no unexpected occurrence to go unexplained – it will eventually bite you in the butt. Most engineering/construction errors are foreseeable, but occasionally there are bizarre

once-in-a-lifetime eye-openers.

Continuity of Long Interconnecting Lines A new SRU received amine acid gas from an off-plot Regenerator at one location, and NH3

acid gas from an off-plot Sour Water Stripper at another location. Operators proceeded to N2-purge the amine acid gas line from the Regenerator to the SRU. While waiting patiently for a sign of flow, the SRU operator noticed vent gas from the NH3 gas line. What started out as amine acid gas terminated as NH3 gas, and vice versa.

To compound the irony, a 4 x 4 was found inside one of the lines upon cutting into a random elbow on the pipeway to install crossovers.

Debris Another 4 x 4 (different project) was discovered when removing an orifice plate in the

course of troubleshooting high indicated flow. (After the second 4 x 4, one has to wonder how many more are still out there.)

20 LLD-020 Startup Lessons Learned


Pump Rotation When performance of a turbine-driven recycle water pump proved extremely poor during

initial run-in, an operator noticed opposing rotation arrows on the pump and driver. Reverse rotation of electric pumps is not unusual because it simply means that power was incorrectly connected, and easily remedied. Turbine mis-match, however, is arguably an inconceivable design error. (WorleyParsons was not the detailed engineering contractor.)

Flow Direction The potential for installing check valves backwards is so obvious that most would probably

expect it to be caught during punch list execution. In one case the incorrectly welded check valve on the steam from the Waste Heat Boiler was apparently insulated before inspection. The problem was discovered when the PSVs lifted during initial lightoff.

On another occasion maintenance personnel were instructed to reverse a check valve. The foreman was later embarrassed when the process engineer called attention to the fact that the valve had been re-installed in the same wrong position. The foreman was unquestionably competent, he just took something for granted without realizing it.

It is not unusual for flow element transmitter leads to be reversed. With orifice plates, for example, the problem usually becomes obvious because indicated flow is zero, if not negative. Venturi meters, however, as commonly used on combustion air, will appear to indicate normal flow (but erroneously low).



Tail Gas Butterfly Valves Some butterfly valves have square shafts, making it easy to mount the actuator

incorrectly if the valve position is wrong. On one occasion personnel were stationed at the valve platform to verify proper

movement when SRU tail gas valve pairs were simultaneously switched for the first time, with instructions to promptly advise the control room by radio if the closed valve did not start to open as the open valve closed. When the closed valve in fact failed to open the console operator reversed the hand switch, but the valves failed to respond because the plastic plugs in the actuator air vents had never been removed. The sulfur seals were blown and the new concrete painted yellow.

Steam Tracing If screwed steam tracing connections will be covered by insulation, perform a service

test before the insulation is installed. Pump Pipe Stress Be concerned when workers need a come-along to mate up pump-pipe flanges. Undue

pipe stress can cause misalignment. Sabotage Intentional construction errors are not typically a concern, but in one case animosity

between rival craft unions prompted some activists to randomly install composition pipe flange gaskets with no ID.



Flow Transmitter Pressure Compensation Occasionally the pressure compensation signal for measured gas flow will be taken from

the wrong transmitter – for example, downstream of the control valve instead of upstream. Relative air/gas flow accuracy is particularly critical at the RGG, and in one case this grossly understated the air/gas ratio resulting in severe sulfation of the pre-sulfurized hydrogenation catalyst upon activation. Proper air/gas accuracy should be verified by preparing a burner curve such as the following.

23

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5

O 2, %

-vol

(dry

bas

is)

Air/Gas

Flue Gas O2 vs Air/Gas Ratio

stoichiometric air

LLD-020 Startup Lessons Learned


The following presentation was made at the 2011 ABPG annual meeting describing major failure of reaction furnace refractory during hot standby, including root causes, lessons learned and recommended operating guidelines.




















Response [LLD-019]: I suspect adiabatic flame temperature is only half the story. With reference to page 7 highlights of attached paper (LLD-019B; Flame Temperature Issues in SRU Equipment) presented at Vail in 2005 by Dave Sikorski, radiant energy is significantly increased with sub-stoich HC combustion, undoubtedly translating to higher refractory temperatures. In retrospect I have observed this but did not really understand or appreciate it until now.


We cannot solve our problems with the same thinking we used when we created them.

Albert Einstein

44

http://www.brainyquote.com/quotes/quotes/a/alberteins121993.html�

Documents

ABPG member individuals or companies. - Brimstone STS tank. 10 Sulfur Collection Header Configuration ABPG Lessons Learned 2012 11 Flange to Sulfur Collection Header Detail Area of