P&ID valve symbols

P&ID valve symbols

What is pressure?

Pressure: It is defined as Force per unit Area. P = F/A

Units      : bar, Pascal, kg / cm², lb / in².

PRESSURE CONVERSIONS

PRESSURE CONVERSIONS :

1psi =	27.74 " H2O
1 Kg/cm2 =	14.223 psi
1 Bar =	14.504 psi
1 Kpa =	0.145 psi
1 Kg/cm2 =	10.000mm of H20
1 Bar =	1.0197 Kg/cm2
1 Kg/cm2 =	0.98 Bar
1 Torr =	1 mm of Hg.

PERMITS SYSTEM

SAFETY - PERMITS

1.    POLICY

It is the Company Policy to require a permit for hazardous work to assure safe operating practices and conditions.  Situations requiring a Permit include Confined Space Entry, Welding and Cutting. and Excavations.

2.      RESPONSIBILITY

2.1       Owning Supervisor

The “owning supervisor” is defined as the individual who supervises the personnel performing the operating functions in the various areas.  The owning supervisor is directly responsible for the area involved. for the safe conditions of work in that area. and for arranging the preparation of the equipment for hazard and entry permit work.  This responsibility applies even though the owning supervisor may utilize the services of qualified subordinate personnel to help expedite the issue of permits.  He is responsible for seeing that any special precautions that must be taken to make the job safe are listed on the permit.  He is responsible for seeing that a detailed check of the preparations for the work has been made.

2.2       Shift Supervisor

The shift supervisor within an operating unit is responsible for approving any work done in the unit.  He must approve all hazardous work permits in his operating area to signify that he is aware of the work being done.

2.3       Safety Inspector

It is necessary for a safety inspector to sign a permit for work to begin. once the permit has been approved by an authorized permit writer from within supervision.  Once the permit is issued, a safety inspector or a supervisor must also periodically review job conditions for safety as the work progresses.

2.4       Maintenance Supervisor

The maintenance supervisor must instruct the maintenance mechanic responsible for carrying out all precautions specified on a hazardous work permit.  In the absence of the maintenance supervisor, the .owning' supervisor will assume this duty.  If during the period of the permit it is necessary to change personnel doing the work, the maintenance supervisor is responsible for instructing the new crew.

2.5       Maintenance Mechanic

The maintenance mechanic is responsible for carrying out all precautions specified on a hazardous work permit accepted by him.  He should report any unusual conditions encountered to operating personnel of the area involved.  He should be particularly alert to changing conditions created as the work progresses.

2.6          Corrosion Engineer

The corrosion engineer is responsible for determining pipe thickness and approving any welding on pressurised piping and equipment including hot tap procedures used.  His approval signature will be fixed to the hazardous work permit.  In addition, the operations supervisor and technical supervisor must approve such work.

2.7          Electrical Maintenance

The instrumentation/electrical engineer is responsible for determining the electrical energy a workman could be subjected to when requested to perform work on an electrically energized circuit safely.  He will then obtain all required approval signatures prior to the start of work. (DC power is excluded from this requirement).

3.         GENERAL RULES

3.1       Permits are valid for one eight hour shift only and issued by a qualified permit writer.  To extend a permit, the oncoming owning supervisor and the responsible operator must recheck the work in progress and sign the existing permit.  Occasionally permits will be issued for longer or shorter periods as determined by the co-signers. If in the opinion of any one of the above mentioned persons, conditions change, making further work unsafe, the work will be discontinued.  Work can then continue only upon express consent of the owning supervisor.

3.2       During plant emergencies. all permits are automatically canceled Work will not be resumed until all areas have been pronounced clear by the Emergency Director.  Permits must be initiated as new work.

3.3       If cutting or welding is involved, fire extinguishing equipment shall be present at the work location with the standby man or safety watch.

3.4       A safety inspector will be required to remain at the hazardous permit location when deemed necessary by the owning supervisor.

3.5       The hazard permit will clearly describe the work location, and the permit will not be construed to include any location other than that designated.

3.6       The craftsman signing the permit shall be given the RED copy (for hot work and vehicle entry) and the BLUE copy (for confined entry).  He must retain these copies at the work site until the permitted time expires or when the work is completed.  He should then sign his copy and hand it back to the owning supervisor.

3.7       The owning supervisor should place the WHITE copy (for hot work and vehicle entry) and the GREENCOPY (for confined entry) in a p I ace within the control center so that persons working in the area will know that hazardous work is in progress.

3.8       Once permits are issued, a safety inspector or a supervisor will make appropriate checks while the job is in progress.

4.  SPECIFIC RULES

The following rules shall govern specifically those conditions which must be met when a decision is made to permit a hazardous job:

4.1       Confined space tank. vessel or excavation entry: visual inspection of inerted vessels.

          Definition

An entry permit Is required before any person may enter a confined space such as a tank, vessel, or pit/excavation deeper than five (5) feet.  Visual inspection of a vessel interior that is inerted or may contain carbon monoxide requires a permit.  A 'vessels is any piece of equipment which must be entered through a manhole or restricted opening. "Entry' means whenever the plane of the vessel opening, confined space, tank. or excavation is broken.

Procedure

1.       An entry permit is required prior to entering any confined space (tank, vessel, pit etc.) or excavation deeper than five (5) feet.  Sump pits with permanent air blower are excluded.

2.       For any entry permit to be approved, initial monitoring of the space to be entered will be completed to assure a minimum of 19.5% oxygen.  “zero” percent combustible vapors. and safe limits of other possible contaminants.

3.       In addition to initial monitoring, continuous monitoring will be done to assure that the above prescribed safe limits are maintained within the space to be entered.  A change of conditions within the confined space can occur from the work being performed within the confined space. as well as from other sources.

4.2         The blue copy of the confined entry permit will be affixed to the confined space to be entered as part of a sign stating a manhole watcher is required.  The work permit will be removed at the end of the job and be handed back to the owning supervisor.

4.3         All piping connected to equipment to be entered shall be Isolated to prevent the entry of contaminants or hazardous material while personnel are inside.  See A.P. “Blinds Installation and Removals”.

a.   All chemical lines (either liquid or gas), all inert lines, and all live steam lines shall be physically disconnected (with blind flanges over the vessel openings) or shall be blinded with suitable slip or figure eight blinds, as close to the vessel as feasible.  All blinds are to be spread on the vessel side.

b.   Water lines and low pressure. low temperature condensate lines (With temperatures below 55 degrees Centigrade) may be isolated by double block valves having an open bleeder connection between.  These valves must be danger tagged.  Reboiler steam and condensate lines must be double block and bled, and danger tagged (see A.P.25)

4.4         Ventilation shall be adequate to provide safe breathing air and to remove excess heat.  All manholes will be open, all air movers shall be set up to blow out.  Only air shall be used to drive air blowers.  Portable A/C are permissible when inlet air is not contaminated.

LOCKING OUT OF EQUIPMENT

1.   POLICY

A lock-out procedure is required to prevent accidental operation or energizing of equipment which could cause injury or damage.

A “lock-out” device is a mechanism or arrangement that allows the use of key operated padlocks to hold a switch lever or valve handle in the “OFF” position.

All equipment having moving parts driven by electric motors or similar drivers or containing elements or parts which may be electrically charged will be deactivated so that they cannot be started or charged during inspection. maintenance or repairs.

Whenever accidental or inadvertent operation or energizing of equipment can cause injury or equipment damage the equipment must be physically padlocked out of service.  This will generally apply whenever an employee is required to clean, repair, dismantle, service or inspect equipment or systems.  In most cases this lock-out procedure only applies to electrical lock-out However, valves are included in some situations as explained in item 2.2 of this procedure.

2.      PROCEDURES

          Deactivating Equipment

a.            Safety padlocks will be used to lock machine controls in the “OFF” position prior to inspection, maintenance or repair work.

b.            Safety padlocks will be provided by the Safety Department to operations units and to designated maintenance personnel.

c.            Safety padlocks will be provided with one key only.  No locks will be keyed alike.

d.            By use of multiple lock adapters, both maintenance and the involved area unit supervisor will place safety padlocks on the main switch and lock it in the open position.

e.            If more than one maintenance craft is involved, each will attach his lock to the switch.

f.            Both Maintenance and Operations personnel will try the switch or switches to be certain that the equipment has been deactivated.

g.            As the mechanics finish their work, they will remove their locks, with the Operations lock being the last lock removed.

h.            In the event of a change of mechanics, the mechanic being relieved will remove his lock and the relieving mechanic will apply his lock before starting to work.

NAME:   Remote switches are not to be considered as lock-out points.  Only main switches or breakers will be used to lock out equipment.

Valves

Valves which could result in Injury or damage if operated will be tagged out in accordance with Tag Out procedure.  For high hazard systems, locking, blinding, or disconnecting is required by Operating Department standard operating procedures (Hot Work Permits or Entry Permits) in Ileti of tagging.

4.5    A standby man will be assigned by the supervisor of the work involved and will be continuously present outside the opening of the confined area when personnel are inside.  The standby man will be instructed In the applicable rules and procedures and will be responsible for the safety of all personnel inside.

Rescue, retrieval and communications equipment will be in the immediate area.  The standby man will be instructed that under no circumstances is he to enter the confined space', during an emergency he will sound the alarm and assist rescuers from outside of the space.

A person entering a confined space will wear retrieval harness, life line and other prescribed equipment as determined by the hazard assessment.

4.6  Hazard Assessment

Prior to any confined space entry permit approval. a hazard assessment will be completed by the owning supervisor.  A hazard assessment is a determination of possible hazards to be encountered in the space, particularly as a part of the work to be performed.  The hazard assessment is complete when appropriate safety control/measures have been implemented.

NOTE:       The safety department must be Involved in the hazard assessment.

4.7     During plant emergencies all entry permits are canceled until all areas have been pronounced clear by the Emergency Director and the vessel has been re-inspected by the owning supervisor in whose area the vessel is located.  During the period of cancellation. all personnel will exit the vessel or confined space and report to their emergency stations All entry permits are canceled during electrical storms.  Personnel will not remain inside or on a tower during this time.

4.8     A hazardous work permit must be written and approved for any work of a spark producing nature inside of a confined space.  This is in addition to the posted entry permit.

4.9     Low voltage of AC 24 volts or less shall be required inside a vessel to reduce the electrical shock hazard.  A transformer of sufficient rating should be used to step down voltage to 24 V. A breaker with Ground Fault Interrupter Circuit (GFIC) should be provided.

5.    WELDING WITHIN TANKS AND TORCH CUTTING INTO LINES OR VESSELS

5.1    A hazardous work permit is required prior to performing heat or spark producing work within any line or vessel.

  Exception

  Lines or vessels being fabricated in construction areas or maintenance shops.

5.2     All piping connected to tanks, vessels. or lines to be cut into or welding performed within, shall be isolated, either before or after cleaning, to prevent the entry of contaminants or flammable materials.

a.       Lines containing flammables and live steam shall be blinded.

b.       Reboiler steam and condensate lines may be isolated.

5.3    A standby man with suitable fire extinguishing equipment shall be present at the work location.

5.4    When heat or spark producing work is being done in a pump alley or near a flume, the flume shall be covered with a fire proof blanket for 20 feet on each side of the job.  The blanket shall be kept wet down with water while the work is being done.

6.    OPENING MANHOLES ON PRODUCT STORAGE TANKS IN OR OUT OF SERVICE

Product storage tanks may contain a nitrogen blanket or contain a product which is immediately dangerous to life safety.  It is for this reason that the opening of manholes on product storage tanks. whether in or out of service, require a permit to be issued prior to the manhole opening.

HAZARD PERMIT                       SIGNATURES REQUIRED

To enter a tank, or excavation                         Owning Supervisor

deeper than five feet. (Sump pits                     Approved Permit Writer

with air blower excepted).                               Safety Inspector

To perform heat or spark producing                Owning Supervisor

work and/or operate heat or spark                   Maintenance Supervisor

producing equipment In areas requiring           Approved Permit Writer

the use of atmospheric testing                          Operator's Initials

instruments - specifically within                      Safety Inspector

a process line or vessel.

To perform heat or spark producing                Owning Supervisor

work and/or operate heat or spark                   Maintenance Supervisor

producing equipment in areas not                    Approved Permit Writer

requiring the use of atmospheric                      Safety Inspector

testing equipment.

To perform work on electrically                      Owning Supervisor

energized circuits above 110 volts                   Maintenance Supervisor

AC or DC. unless conditions listed                  Safety Representative

in section 8.4 of the SAFETY (Permits)

Manual are met.

To perform welding and/or hot tapping           Owning Supervisor

on pressurized equipment.                               Maintenance Mechanic

Maintenance Supervisor

Safety Representative

Corrosion Engineer

Operator’s Initials

NOTE:    THIS BULLETIN ONLY COVERS THOSE PERMITS THAT ARE USED ON A REGULAR BASIS.  REFER TO THE SAFETY MANUAL FOR FULL DETAILS OF ALL PERMITS AND CONDITIONS OF ISSUANCE.

         Electrical Lock-Out

a.. Three Phase Systems - The breaker will be shut off and padlocked. Lock-out of local control 'OFF-ON' switches is not an acceptable electrical lock-out.  Any equipment that is being permanently dismantled must have the electrical leads disconnected at the motor control centre, the wires pulled out of the motor control centre. taped together and left in the above motor control centre.  These wires should be left with a permanent tag identifying their previous service.  On the motor end, all wires will be taped and left enclosed in an electrical fitting.

b.  Single Phase Systems - Includes motors both 110 and 220 volt, solenoid valves, pressure switches, pilot devices and field powered instruments.  The preferred way to lock-out these devices is to padlock the control switch located at the device itself.  If the device does not have a switch, then to lock-out, the power must be turned off at the lighting panel and a "DANGER' tag attached.

3.       PREPARATION

Operating personnel will prepare and lock-out equipment prior to turning over the equipment to Maintenance.  The Maintenance craftsman involved will then apply his lock.  In most cases, the lock-out only applies to electrical equipment; however, as mentioned in (1) above, in certain situations it can apply to valves.

4.       EMERGENCY REMOVAL

The Safety Department may remove a safety lock but only in an emergency and after checking with the involved Maintenance and Operations supervisors.

                   BLINDS INSTALLATION AND REMOVAL

1.      POLICY

The Operations Department shall be responsible for isolating any equipment in need of repair by providing maintenance with a schematic and blind list of the equipment showing necessary disconnect and/or blinding points.

The Operations Department has primary responsibility for all blinds installed in any operating area and will provide blinding instructions for major pieces of equipment.

However, before blinding any relieving device that is in operation, it will be necessary to secure a Hazardous Work Permit from the Safety Department signed by the Safety Representative and Owning Shift Supervisor and to follow the procedures outlined in AP 2.14 of the Safety Manual entitled "Block Valves Before/After Pressure Relief Devices.

2.       PROCEDURES

A)           Each blinding instruction form goes into a plastic envelope and is attached to the piece of equipment.  On major turnarounds. these forms will be used in conjunction with the master shutdown list located in the Control Room.  Unit and Maintenance supervision are responsible for updating the master shutdown list.

B)           All blinds installed shall have either an ear which extends a minimum of two inches beyond the flange or shall be a figure eight blind.

C)           All blinds shall be installed so that the ear or figure eight extension is clearly visible from the platform or slab below the blind.  Yellow streamers should be attached for positive identification.

D)           Drawings of each major piece of equipment showing blind locations will be provided by all units.

E)            Blind lists will be maintained by the responsible operating area on all blinds installed.  The blind list shall consist of the blind tag number, blind location, line size. date of installation, date of removal. and the initials of the Shift Supervisor on duty at the time of removal.

F)            Numbered metal tags will be issued by the responsible operating area far each blind installed.

G)           The metal tag will be wired to the blind at the time of installation by Operations and returned to the responsible operating area by Maintenance for log check-off when the blind is removed.

H)           When the blind tag is returned, the date of removal will be noted on the blind list and the metal tag returned to Its proper location on the blind board.

I) The responsible operating area will visually check each blind location when tags are returned to assure that 'in facto the blind has been removed.

J)            All blinds must be constructed of the same material as the equipment to be blinded.  Deviations may be obtained when equipment is to be completely drained and cleared, but any deviation must be approved by the Unit Supervisor and Safety Supervisor.