Lockout Procedures for Power Plant Equipment PDF

Plant Safety Programs • Chapter 2 OBJECTIVE 4 Describe methods of equipment isolation and lock out. lOCKOUT PROCEDURES FOR POWER PLANT EQUIPMENT Note: Specialized internal training is required for both workers and lockout installers. Please adhere to site-specific training requirements. Lockou...

Plant Safety Programs • Chapter 2 OBJECTIVE 4 Describe methods of equipment isolation and lock out. lOCKOUT PROCEDURES FOR POWER PLANT EQUIPMENT Note: Specialized internal training is required for both workers and lockout installers. Please adhere to site-specific training requirements. Lockouts Lockouts are an essential part of replacing, repairing, and maintaining equipment. The Power Engineer is usually responsible to put equipment in a safe state before it can be worked on. The term "lockout" refers to the placement of a lock on an energy isolating device. This ensures that while the equipment or process is locked-out, it is impossible to energize, startup, or release stored energy during work activities. Energy isolating devices include: • Valves • Blinds • Blanks • Breakers • Disconnect switches Before work begins, all energy sources for the equipment must be de-energized with securing devices such as locks and chains. This is a safeguard, so that no one can operate or interfere with the equipment being worked on. Sometimes, in addition to the installation oflocks, equipment may need to be rendered inoperative by the removal of parts, placing blocks, or pinning equipment to prevent motion. Whichever method is used, it must provide a level of protection equal to, or greater than, that achieved by locldng and tagging. In a safety lockout, all energy that can harm a worker must be de energized. When it comes to safety, there are no shortcuts or relaxed procedures. If equipment is locked out, it cannot be interfered with in any way. There can be serious consequences for doing so. It may be possible to force the valve to move while it is still locked out - but do not do it. No one can remove personal safety locks other than the owner of those locks. Some Jurisdictions permit other "securing devices" for lockout use besides locks and chains. These may include various wire car seals. A car seal is a one-time seal, made of steel cable or plastic, stamped with a unique number. Be aware of local lockout jurisdictional requirements regarding the use oflocks or car seals. For learning purposes across Canada, the federal legislation is the focus. It effectively covers most generic lockout conditions that may occur in the Power Engineer's work place. 4th Class Edition 3 • Part A 2-17 Unit A-4 • Introduction to Plant and Fire Safety CSA Z460 Control of Hazardous Energy - Lockout and Other Methods There are two types of lockouts: 1. Personallockouts 2. Group or Lockbox lockouts A personal lockout - is performed by an individual. The individual lock owner locks out and safely secures equipment that only he or she will be working on. A group lockout (also known as a lockbox lockout) - is performed by one or two trained individuals. Using a set of lockbox locks, they lock out and safely secure equipment that others will be worldng on. Personal Lockouts a) Each worker in the plant is assigned their own personal set oflocks. b) Few assigned locks are issued. If the worker cannot do a personal lockout of equipment with these locks, then a lockbox lockout will be required. c) All personal lockout locks look identical. Therefore, it is easy to recognize when an applied lock is a personal lock. Each personal lock is identified by a unique number, so its owner can be determined. To help identify the owner of the lock, a "Do Not Operate" tag with personal information may be attached beside the personal lock. d) There is only one key assigned to the holder of a personal lock. No one else has a key. The key must not be given to someone else to use. There may be a copy kept securely in a supervisor's office or safety department for emergency purposes only. e) The holder of the personal lock must carry their personal key at all times. In some plants, the worker carries a personal lock at all times. f) The worker will isolate all harmful energy sources. Then a personal lock or other approved securing device can be applied to each isolation device. g) Personal locks are mainly used for smaller jobs such as locldng out a control valve or a pump. However, personal locks are also used with group lockouts, which will be discussed later. h) The personal locks belong only to the one individual. No one else can borrow them or use them to work under. For example, a second person wants to work on the same equipment at the same time. That person must put a set of personal locks at the same places as the first person before beginning the work. With very few exceptions, NOBODY SHALL REMOVE A PERSONAL LOCK THAT BELONGS TO SOMEONE ELSE! 4th Class Edition 3 • Part A 2-16 Plant Safety Programs • Chapter 2 7 E -------------------------- s: 4th Class Edition 3 • Part A 2-19 ================== Figure 3 - Personal Lockouts Feedwater Supply Header To Boiler Inlet Valve to pump Outlet Valve to pump Strainer Check Valve Minimum Flow Valve Vent Wiring On Drain Motor Off Feedwater Pump Motor Breaker Drain Figure 3 shows a sample lockout for a boiler feedwater pump using the personal lockout method. This pump has been turned off using the normal shutdown procedures. To lockout this pump with personal locks, the Power Engineer would follow these steps. 1. It is best practice to first isolate the power supply for the pump motor. This is done by opening the breaker and/or the disconnect switch. Place a personal lock on the disconnect switch. Try to start the pump using the normal start methods, and make sure it does not start. 2. Close the suction (inlet) valve to the pump. Wrap chains or steel cables to secure the valve handle, so it cannot be opened. Apply a personal lock to the chain or cable. 3. Close the discharge (outlet) valve to the pump. Wrap chains or steel cables to secure the valve handle, so it cannot be opened. Apply a personal lock to the chain or cable. 4. Close the minimum flow isolation valve. Wrap chains or steel cables to secure the valve handle, so it cannot be opened. Apply a personal lock to the chain or cable. 5. Open and apply a warning tag to the drain valve to relieve pressure in the piping system. If left closed, pressurized water may cause injury to workers dismantling the pump. By observing the drain valve, it can be determined whether the inlet, outlet, and minimum flow valves are tightly shut. 4th Class Edition 3 • Part A ==== Plant Safety Programs • Chapter 2 Unit A-4 • Introduction to Plant and Fire Safety ================== ================== 6. Open and apply a warning tag to the pump casing vent, so that all liquid in the pump housing and piping can properly drain. Group(Lockbox)Lockouts Often, many workers are assigned to repair a single piece of equipment. These workers may include electricians, power engineers, and mechanics. A group lockout is designed to protect all workers who are required to work on locked out equipment. Each worker must be satisfied that the lockout procedure is sufficient and sign or initial on the lockout sheet. As well, each worker must verify that the machinery is de-energized and isolated before beginning to work. These tradespeople may conduct their work over a period as stated on the Safe Work Permit associated with the lockout. The group lockout allows each worker to apply a single personal lock in one centralized location, and only for the period of time he or she is working on it. This is accomplished with a lockbox. Figure 4 - Portable Group Lock Box Figure 4 shows a portable group lockbox that can accommodate multiple personal locks and car seals. The portable lockbox is suitable for use in remote parts of the plant that are far away from permanent lockboxes situated in the main operating areas of the plant. Two trained operators normally perform the actual group lockout. One operator is the lock installer and the other is the verifier. A set or sets of group locks are used to do the lockout. Each of the locks in the set are keyed alike, so that one master key can open all the locks of the set. Each set of group locks has a unique identification number with a pre-determined number oflocks (for example, 10 locks in a set). The trained operators apply one group lock from a set at each isolation point, such as the breaker/ disconnect and isolation valves. The master key(s) are placed inside the lockbox along with the lockout isolation sheet and any unused locks from the lock sets that were applied. The operators and workers then apply their personal locks to the lockbox. The master key is sealed inside the box with a car seal. 4th Class Edition 3 • Part A 2-21 == == == Plant Safety Programs • Chapter 2 == As with the personal lockout, the equipment lockout must be verified before work proceeds. Verification proves that: a) The correct breaker was opened. b) All the isolation points were isolated effectively. c) All forms of stored energy have been dissipated. Other workers can now put their own personal lock on the lockbox. Their personal locks now prevent access to the group lock master key. When workers complete their tasks, they must remove their personal locks from the lockbox. The lockbox cannot be opened until all workers' personal locks have been removed - to ensure the safety of all personnel that are worldng on the equipment covered under the group lockout. From time to time, especially during maintenance shutdowns (turnarounds), there can be more than one group lockout in place at the same time. For example, a boiler can typically have separate fireside and waterside lockouts. The plant may also have other lockouts on pumps or other vessels, such as a deaerator, that are inter-related to each other with unclear lockout boundary lines. These situations are called "complex group lockouts:' It is advisable to consult the site-specific policy and procedures, as well as, local jurisdictional regulations addressing "complex group lockouts:' The following is a set of suggested general guidelines suitable for a single group lockout. a) Lockboxes can be located near the work area, process building, permit issuing office, or in some other area (especially during turn around) for viewing. The lockout sheet (described below) is kept with the lockbox for quick reference. b) A written lockout procedure must be completed for a group lockout. The following should be included on the lockout sheet. i. A title that identifies the unit or equipment being locked out. ii. The date the lockout was implemented. iii. Names of the trained individuals that installed and verified the locks on the lockout. iv. Identification of the group lock set and number of locks used for the lockout. Group lock sets should be numbered and colour coded. For example, yellow locks may be designated for operations, red for electrical trades, silver for commissioning and start-up, black for maintenance crews, blue for personal locks, and so on. For example, an operator may have used set #5 of the yellow group locks (designated for operations). This set may have 10 locks in total. The operator may have only used locks 1 to 7. Locks 8, 9. and 10 would be locked inside the lock box. v. A list of all isolation points where a lockbox lock has been applied. It should identify all equipment (such as valves, gates, actuators, dampers, motors, or fans) that could affect the safety of the operator worldng on the locked out equipment. On Track Note: The lockout sheet is often accompanied with a marked up as-built drawing, such as a P&ID (piping and instrumentation diagram). The drawing should clearly identify the isolation points. vi. The car seal number used on the lockbox. vii. A place for initials beside the lockout point entries. This can be a box beside the lockout point on the page, so the operator(s) can initial to verify that the point has been locked out. viii. Equipment that is not locked out, but has had its status changed (e.g. open or shut) to support the lockout. For example, an opened drain valve may be identified as open, but not locked open. This changed state should be recorded on the lockout sheet. 4th Class Edition 3 • Part A 2-19 Unit A-4 • Introduction to Plant and Fire Safety ix. If an electrical breaker lockout for a motor is required at a motor control centre (MCC), a bump test at the local on/offhand switch is performed. The trained operator must prove the motor will not start accidently. The local on/offhand switch is locked in the "off" position with one of the group locks. It is then recorded on the lockout sheet, along with the name and signature of the operator who performed the bump test. x. All involved workers must be identified. Their name, personal lock number, name of employer, sign in/sign out time, and date must be on the lockout sheet. xi. After all work is completed, personal locks will be remove from the lockbox by all involved parties. Then, the car seal is broken to retrieve the master key or keys and the lockout sheet. xii. The trained operator(s) will open the locks, remove locks and chains or steel cables at the isolation points, and return the valves back to normal operating positions. When the lockout is fully removed, the same operator(s) will initial the lockout sheet to sign off. xiii. A supervisor or designate will then verify all locks have been removed. All isolation points are checked to ensure that they have been restored to normal operating positions. When the verification is completed, the supervisor or designate signs off on the lockout sheet with a printed name, signature, and date of confirmation. CAUTION Occasionally, a lockout requires modification. In this situation, all personal locks must be removed from the lockbox. The car seal is broken off so that the master keys of the group locks can be accessed. A site specific "lockout deviation P\rocess" must be followed, in accordance with plant policy and/or jurisdictional requirements. Figures 5 and 6 are samples of the front and back of a typical group/lockbox lockout sheet. 2-20 <(-------------------------------4-t_h_C_Ias_s_E_d_il_io_n 3•_P _a _r_l_A Plant Safety Programs • Chapter 2 Figure 5 - Sample Group Lockout Sheet - Front of Sheet ' Sample Group Lockout Sheet A. Lockout Identification Equipment#: Equipment Name: Lock Box#: Car Seal#: Description of Lockout: B. Lock Set(s) Information Lock Set# Number of Locks in Set: Total Locks Installed: C. Lockout Points Information Lock Set # Lock # Description Locked Position LC (Locked Closed) LO (Locked Open) Operating Position NC (Normally Closed) NO Lock Lock Lock (Normally Installer Verifier Remover Open) (Initials (Initials) (Initials) 4th Class Edition 3 • Part A 2-21 Unit A-4 • Introduction to Plant and Fire Safety Figure 6 - Sample Group Lockout Sheet - Back of Sheet D. Lockout Installed by: Print Name: Personal Lock #: Signature: Date: Personal Lock #: Signature: Date: E. Lockout Verified by: Print Name: F. Motor Bump Test Confirmed by: or Print Name: o N/A Personal Lock #: Signature: Date: Personal Lock #: Company Name: Time In I Initials: G. Workers Sign On/Off Print Name: Time Out/ Initials: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. H. Lockout Removal Sign Off All locks have been removed and all isolation points have been restored to normal Operating positions. Confirmed by: Print Name: 2-22 Signature: <(-------------------------------4-t_h_C_Ias_s_E_d_it_-n-3• P __ an _ _A Date: Plant Safety Programs • Chapter 2 CHAPTER SUMMARY Having a functioning Occupational Health and Safety (OH&S) program is a license-to-operate. It is a defined plan of action to prevent accidents and incidents from occurring at the workplace. Its specific focus is to keep workers safe and alive. The elements for the (OHS) program presented in this chapter serve as general guidelines for the implementation of a site-specific program. The safety training discussed requires both external and internal qualification for a worker to be proven competent to work under these conditions and environment. The Safe Work Permit (SWP) a nd Control of Hazardous Energy (Log Out, Tag Out) programs described in this chapter are similar to the ones commonly used in plant sites. However, they are for general demonstration and explanation purposes only. They are not intended to replace the site-specific programs. Please consult site specific and jurisdictional (OHS) policy and requirements for further information. In addition, only qualified and competent operators in the applicable areas are selected to take the training. Only these successfully trained and qualified operators may issue safe work permits, and perform lockouts and tag outs. (