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Guy wired flare structure
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Self supporting flare structure
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Derrick type flare structure
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FG IA & MS BV provides the following services with respect to flare stacks and flaring systems:
Full inspection with video and data on:
- Main stack body
- Flare stack piping works
- Top parts incl. stairway
- Inspection of guy wires
1. Main stack body
- To determine the actual status of the main pipe, the wall thickness is to be measured at 20 cm x 20 cm locations all around the pipe by U.S. thickness measurement.
- The coating layer and conditions are to be checked.
- Bolts and nuts are to be checked.
- The inside of the main pipe status is to be checked for any damage, especially the bottom of the pipe and the locations around the welding spots.
- The vertical position of the stack pipe is to be checked.
2. Flare stack piping works
- Main piping status is to be checked for fitting and condition of :
- bolts and nuts
- insulation
- welding locations
- supports
- expansion slots
- flance joints
- Mainsteam pipe's thickness by U.S. measurements next to any joint at both sides of the joint, 360° check.
- Gaspipes and steampipes are to be checked for coating layer conditions.
- All fitted pipes have to be run parallel to the main stack pipe. Expansion parts should be checked for free movement capabilities.
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FG on the site
FG on the site
FG on the site
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Flare tip exchange
Guy wire tentioning
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3. Top parts incl. stairway
- Tip body
- Pilots
- Ignitors
- Gangway around the tip is to be checked on corrosion and mechanical damage
- All piping, supports, bolts and nuts are to be checked for corrosion and mechanical damage
- Stairway is to be checked from bottom to top including supports. Coating layer condition is to be checked
- Thermo couple's wiring is to be checked
- Smoke detonator
4. Inspection of guy wires
- Status of all equipment, parts and peripherals are to be checked. Damage is to be checked and reported combined with status of safety when in use.
- All original drawings are to be taken as "status to be", or as indicated otherwise.
- All situations regarded as not safe for operation within the next 4 years are to be reported immediately to the inspection department.
- Dead weights.
- Tentioners, turnbuckles, shackles and clamps
- Cable protection
- Corrosion at cable
- Prevention
- Earthing
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Maintenance:
- Replacing flare tip without a crane (winch hoist installation)
- Replacing guy wire/retentioning
- Replacing piping/wiring
- Recoating guy wire
- Recoating stack pipe
Cost reduction:
- Project lead time very short
- all know how on site
- no cranes, scaffolding needed
- no cost due to weather delay
- All actions are video recorded
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Derrick structured flare
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Flare tip lifting device
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Flare tip lifting
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Flare tip replacement
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Different types of flare stacks
Three types of flare stacks can be distinguished:
- The free standing guy wired flare stack with only one major pipe going up. The height of these flare stacks varies between 60 and 240 meters
- The derrick type flare structures, where a steal construction supports one or more flare pipes
- The free standing flare stack that does the job without being suspended or supported by any additional structure
All structures have in common that they make use of a flare tip. This tip is located at the end of the pipe and takes care of igniting the combustible gases. Normally a significant amount of steam is injected in the flame to reduce soot and the building of large flames together with cooling the flame base. This means that a lot of steam has to be transported to the top of the flare. Flare structures need to be inspected and maintained on a regular basis according to the time in between the turn-around or stop intervals of the plant.
Inspection and maintenance can only be done when the flare is turned off completely. This means that it needs a total shut down of all the facilities connected to this flare. The flare stack itself is like the exhaust system of a motor vehicle, which means that without the flare the plant cannot produce any products. Once the flare produces a problem you can only do something by shutting down the entire plant which results in a large loss of production and therefore a loss of money each day the plant is down due to flare failure.
Maintenance aspect
A flare tip is usually inspected every 2 years (if possible to tie in with shutdown) and a well operated tip can last from 6 to 10 years. During the inspection, the tip is inspected for the following:
- Shell thickness (internal and external)
- Refractory lining (if any)
- Ignitor
- Main and pilot nozzles
- Thermocouples
- Steam / air piping
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Flare tip replacement
Typical winch set 1 x 2 ton, 2 x 500 kg pneumatic
Flare tip
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Flare tip changeout procedure
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Successive stages in flare tip replacement |
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- Before commencement of the actual work, the flare platform structure is inspected for rigidity and status of maintenance. In case of a negative outcome, additional supports can be fitted to ensure safe working loads on the existing structure. This is carried out in co-operation with the principal.
- The main winch and the assisting winch are installed at around the base of the structure.
- The Lifting Arch Frame (LAF), weighing 300 kg, is hoisted up. Each piece of the frame structure weighs about 16 kg. It is made of an aluminium alloy that has a high strength to weight ratio. It is capable of lifting 5 tons load, and flare tips usually weigh about 1 ton to 3.5 tons.
- The LAF is positioned against the flare tip and braced along side the tip.
- Every single part that has to be fixed at the top, is secured against falling down from the top of the boom during the installation works.
- The LAF's forward and backward movements are executed by chains that secure the parallel position as well.
- The blocks, tackles and winch cables are fitted to the flare tip.
- The bolts on the flare tip are loosened and lifted up just 50mm with some bolts still in, but with loosened nuts. This is a trial test which is usually required by the local authority as a safety procedure.
- If the tip is balanced, the remaining bolts are removed and the tip is lifted high enough to clear the platform while leaning forward out.
- During heavy weather, guiding cables can be used to ensure that wind will not sway the tip in an uncontrolled manner while being lowered.
- The winch is located about 30 meters away from the base of the stack so that no one is in the drop line of the load. The area below the stack will be condomoff, no other personnel may be permitted to enter without first notifying FG personnel.
- When the tip is safely down, the new tip can take the place of the old one or the old one is being repaired and hoisted up in reverse sequence of this procedure.
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Replacement procedure
Flare tip replacement
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Should a tip require repair, it can be brought to the main platform without using barge crane or
scaffolding. In this aspect, FG method is the most suitable as it can be done at a minimum cost.
Flare tip revision overview for a slanting boom:
Pos. 1: Serviceability position
Pos. 2: Hanging in crane (upper position)
Pos. 3: Hanging in crane (lower position)
Pos. 4: Hanging in conduction cable (contact free)
Pos: 5: Hanging in conduction cable (free position)
Pos. 6: Hanging in conduction cable (upper position)
Pos. 7: Hanging in pulling cable
Pos. 8: End position
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For a slanting boom
procedure
- FG equipment is brought to the platform via a small barge and is hoisted onto the platform using the existing platform's crane (if any). If not available, FG can bring their own equipment up to the platform via a portable manual winch.
- Assuming that the tip needs repair and can be done on the platform itself, the tip is advisable to be brought to the platform.
- FG Arch-Frame is erected over the flare tip.
- Two guide wires are pulled to the main-platform.
- The flare tip is lifted up and hooked onto the 2 guide wires.
- The flare tip is brought to the platform via these two guide wires.
- Repair is carried out on the platform.
- Installation of the repaired flare tip is the reversed of the above procedure.
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FG has been doing lots of flare tip replacements and inspections for the offshore platforms in a number
of places.
Advantages
- Flare tip exchange can be carried out quickly
- Location on top platform is fully accessible
- Use of certified materials only
- All preparations can be executed up to a wind speed of 15 m/s
- Hoisting process can be continued up to a windspeed of 10 m/s
- Fast reaction time when weather changes compared to helicopter
- The load to be hoisted is always fully under control
- Hoisting system has been designed completely failsafe and is being deployed for over 6 years without any incidents
- The system is safe and friendly for the crew working with it
- All crew members have offshore safety certificate
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Tip inspection
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Many flare installations have their flare structures in service for many years. In some cases, inspection and maintenance of the structures cannot be carried out without a complete refinery shutdown. FG Engineering Services BV has developed an innovative method of inspecting and maintaining flare structures and the flare pipeworks while the flare is still LIVE!!
Using abseiling techniques, FG can completely inspect the flare structures while the flare system is live. The risks involved were fully understood and precautions were taken to ensure the safety of the personnel, in case of an emergency burst out.
The potential risks were jointly analysed by FG and the client operation and inspection staff. As a first step, the heat flux that could occur in the event of a flare incident was calculated. The wind velocities, direction and magnitude of flaring were also taken into account.
Method
- A hydro-shield was first installed at the top of the flare structure under the protection of water canons and fire engines. This is the only time that the men are exposed to the danger of emergency flaring.
- After the hydro-shield is installed, it will be safe to work below it. While working on the flare, the hydro-shield will be activated in case of an emergeny.
- This will form a water curtain that will shield the men working inside the structure from the flare radiation.
- Once the hydro-shield is activated, FG personnel will stop working and proceed with the evacuation routine. Our men are equipped with a double line personal escape device that will enables them to be back on the ground within 10 seconds.
- The design of the hydro-shield will take into consideration the maximum amount of flaring possible.
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Hydro shield
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Installing lift arm at next level
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Lifting next pipe part and place it at the top
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Flare tip final part
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Flare tip final part
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For the erection of the flare structure, FG IA & MS BV can provide you with the following services:
- A professional erection team consisting of:
- Mechanics and riggers certified to use the rope access method for abseiling
- Site manager for organising the project planning team and to attend liaison meetings with owner, contractors etc.
- Certified welders for execution of the two site welds
- Cranage of the equipment by one small 20 Mtons for support during the assembling at ground level and a 300 Mtons mobile crane for erection of the major construction parts and flare tip; including all necessary lifting lugs, slings etc.
- For the assembly we will provide all necessary tools, based on the assumption that all joints will be of bolted connections apart from the two specified field weld joints which are included in our scope.
- Consumables such as welding rods & gas, fuel etc. are included. For the necessary electrical power we assume that we can make use of the available site provisions.
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The main goal of inspection is to obtain relevant information about the present condition of steel, concrete, coating and other parts, as a result of weather conditions, fatigue of metals and other influences that effect the maintenance condition of the tank, and the expected developments in maintenance condition.
FG IA & MS BV applies a.o. NDO-techniques for inspections, with video techniques as most important tool. Some examples of inspection techniques are endoscopic inspection, MPI, thickness measurement of coatings, concrete quality inspection and ultrasonic thickness measurements.
After every inspection a written report will be made up, supported with video images and photographs.
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Sphere tank
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Sphere tank inspection (external)
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Conventional method: by scaffolding
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Conventionally, to inspect a sphere tank internally and externally, scaffolding has to be erected for access. Due to the curved surfaces, erection is both time consuming and very difficult. For a 20m-diameter tank, the scaffolding would normally take 10 days to erect and another 4 days to dismantle. Beside these, adjustments to the scaffolding during the course of inspection are also a frequent occurrence as the scaffold pole may stand directly on a weld seam that needs to be inspected. All in, a full inspection of a sphere tank will take about 30 to 35 days.
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The FG method
Access via abseiling
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The FG Sphere Frame®
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Sphere tank inspection
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FG developed an innovative method for the inspection of a sphere tank. Access to the external surface is done by rope abseiling, internal access is realised by the FG Sphere Frame®. In no more than 2 days the FG Sphere Frame is erected, and is dismantled in just 1 day, thus saving 10 days on scaffolding erection. The FG Sphere Frame is a plane structure that can rotate inside the sphere about the vertical axis, thereby allowing all surfaces to be accessed. The inspector easily executes rotation inside the sphere by raising the structure 10mm by means of a block and tackle, after which he only needs to push his hands against the shell. On reaching the spot he wanted, he just lets the structure rest on its rollers by lowering it. A full inspection can be completed within 16 days. All gritblasting, inspection, painting and erection will be co-ordinated by FG trained personnel, so that minimal time is wasted on liaison between different parties. Not to mention the savings on scaffolding costs internally and externally.
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A full service package:
- Internal access (no scaffold/cranes)
- External access (no scaffold/cranes)
- U.S., MPI, visual inspection both internal and external
- If required, access to the internal sphere for third party personnel is provided, for specialized welding and cutting
- FG Sphere Frame® is stable, solid, light weight, easy to move and cannot damage the sphere structure
- Central filter pipes can be left inside
- Very short installation time: 20 mtr sphere in no more than 2 days
- By providing the full service package, project time, and therefore the sphere's off line time, is minimized
- Savings are substantial: both from cost reduction and strongly reduced off line time
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Storage tank
Maintenance and inspection of storage tanks
Often, storage tanks are objects of which parts that need to be inspected are problematic to reach, because of the large dimensions of the tank. By using special techniques, a complete storage tank will be within easy reach, both internally and externally. Because of the working method, FG IA & MS BV provides a complete and efficient inspection of your storage tank.
The inspection and maintenance of the tank is actually an easy job, thanks to our techniques. All necessary maintenance can be carried out from the applied construction, thanks to which the roof, the sides and the floor of the tank are within easy reach.
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The application of video techniques, of which the images are visualised in full color inside an inspection cabin, supports the activities of FG IA & MS BV. This enables you, as employer, to view the activities on-line and, if so wished, to give instructions. On the basis of the obtained information, the activities, such as the inspection, can be exacerbated in co-operation with you or other resorts.
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Inspection cabin
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Internal and external inspection
Storage tank inspection construction
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Storage tank inspection construction
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Single pile stud system
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Trough the application of the special construction inside the tank, the complete inside of the tank becomes accessible for inspection and maintenance. The application of the FG Tank Inspection Construction (FG TIC) makes scaffolding superfluous. All activities can be executed from this contruction, which can be made accessible for third party personnel, for specialized welding and cutting.
By applying rope access abseiling techniques, the entire external surface of the tank can be reached for inspection and maintenance. Again, scaffolding and cranes are superfluous. The examination of pipes, coating and other attachments is easy because of this technique.
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A full service package:
- Internal access (no scaffold/cranes)
- External access (no scaffold/cranes)
- U.S., MPI, visual inspection both internal and external
- If required, access to the internal storage tank for third party personnel is provided, for specialized welding and cutting
- FG Tank Inspection Construction (FG TIC) is stable, solid and easy to move.
- Mounting on, for instance, the frame (internal) and pipes (external)
- Repair of insulation (external)
- By providing the full service package, project time, and therefore the tank's off line time, is minimized
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Quality and safety
FG IA & MS BV keeps its quality and safety under strict
surveillance in accordance with the following systems:
- ISO 9001, certified under number NL04/0220 QA
- VCA*, certified under number NL04/0216 VA
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Chimney access
Storage tanks and spheres, inspection and maintenance without scaffolding
Bridge inspection and maintenance
Endoscopic inspection
Fixing works on large installations; no scaffolding or crane required
Thickness measurement of coatings
Petrochemical plant
Guywire inspection, remote controlled with live transmission (active antennas)
Offshore; spiderdeck, leg, tower inspection/maintenance
The FG JIB®
100 % safe, lloyds certified
Stay cables (locked coil)
Glass pearl blasting of galvanised bridge cables,
100 % environmental safe
Inspection cradle for bridge cables
Integrity check of bridge cable, Ø 110 mm (locked coil)
Bridge cable maintenance
Layer inspection
Reactor inlet nozzle inspection
Venture holes of reactor inspection
FG column inspection
