A Pilot operated relief valve failed to lift during planned recertification in the workshop. The cause of failure to lift identified as a plug fitted in the pilot exhaust port. Plug was removed from pilot exhaust port and RV functioned as intended. On inspection of three remaining RV’s on compressor discharge, it was
found that another RV also had a plug fitted in the pilot exhaust port.
Showing posts with label Mechanical integrity. Show all posts
Showing posts with label Mechanical integrity. Show all posts
June 20, 2022
ARE YOU INSPECTING YOUR PILOT OPERATED VALVES CORRECTLY?
June 4, 2022
ARE YOU INPECTING SMALL BORE TUBING?
An ammonia leak occurred at a commercial-industrial facility. Approximately 10 lbs ammonia entrained in approximately 200 litres of compressor oil was released when a suction side 3/8-inch pressure sensing line failed. The suction side oil pressure pushed approximately 200 litres of oil from the reservoir onto the floor where the entrained ammonia then escaped to atmosphere. The 3/8-inch stainless steel tubing within the compression fitting failed when a circumferential crack completely fractured. The crack within the
3/8-inch stainless steel compression fitting did not show up on external inspection. Metal fatigue appeared to be a factor, along with unit vibration and initial metal stress within this type of compression joint.
The refrigeration contractor identified the main cause and factors leading to the failure as a severe vibration condition of the compressor. This severe vibration condition only occurs when only happens when the control slide valve is at, or at near its minimum position. The vibration was so intense that the contractor immediately shut the compressor down. Also, the contractor’s investigation discovered the ‘PHD’ vibration monitoring system was inactive. When the monitoring system was activated, the compressor in fact shut down on ‘high vibration.’
Source: British Columbia Safety Authority
May 31, 2022
ARE YOUR SAFETY DEVICES WORKING?
Ammonia was released at a recreational facility. A high pressure cut out switch failed to shut down a compressor when the compressor experienced a high pressure condition. Pressure continued to build until a safety relief device operated releasing ammonia gas to atmosphere via the relief stack,
which triggered the ammonia alarm.
The water supply line to the condenser had no protection and was subject to freezing during cold weather. The high limit switch was old (1986) and is mounted on the compressor base subjecting it to vibration. The safety relief operated as designed, venting gas to atmosphere, preventing a possible
catastrophic failure.
Source: British Columbia Safety Authority
April 1, 2022
LOOSE BOLTS - CAUSES
Www.smartbolts.com/insights/loose-bolts-causes-ways-prevent/
A pressurized bolted flange joint assembly begins to leak, creating a
safety hazard. A rotor with its blades separates from the nacelle and
spins off a wind turbine, crashing to the ground. Under constant
vibration from the engine of an ocean freighter, loose bolts on a large
piece of mining equipment work their way off the bolted joints and roll
around the hull, inflicting further damage to the equipment.
March 28, 2022
March 24, 2022
March 16, 2022
Is it Possible to Turnaround a Turnaround? - POWER Magazine
Is it Possible to Turnaround a Turnaround? - POWER Magazine: By Paul Muir, CRO, Mobideo Why are Turnarounds So Challenging “A large turnaround can include up to 150,000 individual activities. With this level of complexity, approximately half of all shutdown projects are delayed by more than 20% and 80% go over budget by more than 10%. Frequently, the work scope increases unexpectedly by up to […]
March 1, 2022
SMARTBOLTS.COM - LOOSE BOLTS - CAUSES
http://www.smartbolts.com/insights/loose-bolts-causes-ways-prevent/
"A pressurized bolted flange joint assembly begins to leak, creating a safety hazard. A rotor with its blades separates from the nacelle and spins off a wind turbine, crashing to the ground. Under constant vibration from the engine of an ocean freighter, loose bolts on a large piece of mining equipment work their way off the bolted joints and roll around the hull, inflicting further damage to the equipment".
November 26, 2021
How to Clean Natural Gas Piping with Gas Blows
How to Clean Natural Gas Piping with Gas Blows: Before new fuel gas piping can be connected to a combustion turbine (CT), it must be cleaned by “decompression” gas blows. Here's how to do it.
November 10, 2021
How to Conduct Steam Blowing Procedures with Remote Personnel
How to Conduct Steam Blowing Procedures with Remote Personnel: Many power projects have been disrupted due to COVID-19. However, managers at Larsen & Toubro Ltd. found a way to complete steam blow requirements in spite of the pandemic, using secure internet
October 24, 2021
Improving Asset Inspections with Drones and AI
Improving Asset Inspections with Drones and AI: The U.S. bulk electric system has more than 360,000 miles of transmission lines, which means power companies have a lot to inspect. Drones and AI can help.
October 12, 2021
Preventing and Mitigating Oil Fires in Power Plants
Preventing and Mitigating Oil Fires in Power Plants: It has been said that a picture is worth a thousand words. However, photos of the conflagrations that have resulted from ignition of minor lube oil leaks on a typical steam turbine room floor will leave you speechless. Full-scale physical simulations of oil fires by the insurance company FM Global leave no doubt that power plant fire prevention and mitigation is a judicious blend of art and science.
September 18, 2021
September 14, 2021
September 10, 2021
May 28, 2021
April 3, 2021
External chloride stress corrosion cracking of stainless steel
https://www.hse.gov.uk/safetybulletins/lokring-pipe-connectors.html
February 12, 2021
September 12, 2020
Inspection frequencies and OSHA
The most commonly cited equipment for non-compliant inspection frequencies (of any type, not only thickness measurements) have been piping circuits followed by pressure vessels, relief devices, and monitoring alarms. As part of the inspection program, an appropriate inspection frequency must be established for equipment in order to determine whether pipe/vessel thickness is decreasing as expected. API 570 identifies three classes of piping services and recommends a thickness measurement inspection frequency based on the class. For example, Class 1 includes:
- Flammable,
- Pressurized services that may rapidly vaporize and explode upon release,
- Hydrogen sulfide,
- Anhydrous hydrogen chloride,
- Hydrofluoric acid
- Piping over water of public throughways, and
- Flammable services operating above their auto-ignition temperature.
As discussed in API 570, Class 1 requires a thickness measurement inspection frequency of at least every five years. Classes 2 and 3 require a thickness measurement frequency of at least every 10 years. The inspection interval for specific piping is established by the inspector or piping engineer in accordance with the owner/user’s quality assurance system, but not to exceed the limits set by API 570
Source:Osha.gov
September 8, 2020
OSHA ASSET INTEGRITY OBSERVATIONS
Examples of equipment cited for violations of the PSM MI requirements that OSHA found during NEP inspections include:
- A broken gate valve caused a level gauge to not work properly, which rendered visual verification of liquid level for the vessel ineffective. This deficiency went uncorrected.
- The installation of an engineered clamp failed to correct a deficient piece of process piping, which was a 90-degree elbow that was outside acceptable limits. The employer continued to use the leaking 90-degree elbow as part of a piping circuit that conveyed waste hydrogen sulfide gas.
- Hydrogen sulfide monitors were not inspected and tested on a regular basis to correct deficiencies in alarms that were outside acceptable limits due to bad sensors, loose wiring, or monitors that needed to be replaced. Work orders were not managed by a tracking system to ensure that deficiencies were fixed in a timely manner. Some work orders marked “fix today” or “ASAP” were not fixed for a week or longer.
- Six relief systems in an alkylation unit were incorrectly sized and were not corrected in a timely manner when the deficiencies were reported. No Management of Change (MOC) was performed to justify the decision to delay replacing the deficient systems.
- Grounding cables were removed from equipment, such as a heat exchanger and pump motors, but were not replaced.
- Excessive vibration was observed on motors with visible movement of structural steel decking and supports. Also, two 1” pipes and one 4” pipe containing flammable liquid were not adequately supported
Source: Osha.gov
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