Skin or eye contact with cryogenic liquids can result in a risk of cold burns, severe frostbite and permanent eye damage. In case of inadvertent inhalation and loss of consciousness, immediately bring the affected person to fresh air in a stable side position and keep the person warm.
In case of respiratory failure, immediately take first aid measures with artificial respiration. Immediately seek medical assistance. In case of inadvertent skin contact, wash the affected skin area with abundant water for at least 15 minutes.
Then cover the affected skin area in a sterile fashion. In case of inadvertent eye contact immediately rinse out with clear water for at least 15minutes including under the eyelid. Danger due to nitrogen or argon! When inhaled, emerging nitrogen or argon in high concentration can cause loss of consciousness with inability to move and can lead to asphyxiation. Always ensure fresh air supply while working with either liquid or gas.
In case of inadvertent inhalation, immediately bring the affected person to fresh air in a stable side position and keep the person warm. Danger due to oxygen! Oxygen in high concentration causes ignition temperatures of flammable substances to be lowered significantly. Liquid or gaseous oxygen in high concentration must not be allowed to make contact with any flammable material. Excessive inhalation of oxygen may cause headaches and dizziness. Danger due to oxygen deficient atmosphere!
When present in areas with oxygen deficient atmosphere, serious injuries or even death can occur as a result of restricted performance capability. Danger due to components exposed to pressure! Components exposed to pressure can move in an uncontrolled fashion and can cause serious injuries when improperly handled.
Liquid can emerge under high pressure from components exposed to pressure and can cause serious injuries or even death when improperly handled or in case of a defect. Risk of injury due to cryogenic surfaces! Surfaces can cool down during operation. Skin contact with cryogenic surfaces causes severe frostbite. Risk of injury due to hot surfaces! Surfaces of components can heat up intensely during operation. Skin contact with hot surfaces causes serious burns.
Risk of injury due to restricted or improper firefighting! If a fire extinguisher is not ready for use or is unsuited for a specific fire class, serious injuries or even death as well as significant property damage can occur in the event of a fire. Danger to life in case of fire due to highly flammable substances! Highly flammable substances, liquids or gases can catch fire and cause severe or fatal injuries.
Handling of open fire and ignition sources of all types is prohibited. Leave hazard area and notify the fire department. Danger to life due to nonfunctioning safety equipment! Safety equipment that is nonfunctioning or is out of operation poses a risk of severe or fatal injuries.
Integration in the emergency shutdown concept is essential The pump assembly is intended for use within a system. It does not have its own control system or an autonomous emergency shutdown function. Before the pump assembly is brought into operation, install emergency shutdown devices on the pump assembly and connect in the safety chain of the control system. The emergency shutdown device s must be connected so that during interruption of power supply or activation of power supply after interruption, hazardous situations for persons and property do not occur.
The emergency shutdown equipment must always be freely accessible to personnel in the work area. Danger from unconnected emergency shutdown switch! The emergency shutdown devices must be installed on the pump and incorporated in the safety chain of the installation control. Integration in a protective fence system required The pump assembly is intended for use within a system. Before the pump assembly is brought into opera- tion, install protective fences around the pump assembly and incorporate them in the safety chain of the con- trol system.
Protective fences must separate hazard areas. The hazard areas within the protective fences may not be entered when the power supply is switched on. Only enter using the doors prescribed for this purpose. Do not engage as long as persons are within the protective fences. Safety valves Safety valves are relieving devices for pressure containing components such as pressure vessels or pipe- lines.
A safety valve is situated in the high pressure system of the pump, which relieves the overpressure without hazard if pressure rises too high as a result of incorrect operation, component failure or other irregular events.
They pertain to the immediate sur- roundings in which they are placed. Risk of injury due to illegible symbols! Over the course of time, stickers and tags can be soiled or become unrecognizable in other ways so that hazards are not recognized and necessary operating instructions cannot be followed. As a result, this poses a risk of injury. Personal protective equipment Wear the appropriate personal protective equipment while working in order to protect against injury. Electrical voltage Only authorized electrical technicians may work in a marked area.
Unauthorized personnel may not enter the marked workplaces or open a marked cab- inet. Cold Warning from hazardous cold in the work area. There is a special risk of frostbite of hands, feet and eyes.
Wear cold-protective cloth- ing. Pull-in hazard Conduct work at pull-in locations only during shutdown. As long as the pump assem- bly is moving there is a risk of injury. Table In order to understand this definition, some background information is required. Vapor pressure is the pressure at which a liquid converts to gas, or the reverse thereof, at a given tempera- ture.
Since the vapor pressure changes with temperature, a curve can be established for a particular sub- stance showing its vapor pressure at any temperature between the triple point where the substance exists simultaneously as a solid, liquid, and gas and the critical point above which the substance cannot exist as a liquid.
All substances have a vapor pressure curve, each one unique to its particular substance. The vapor pressure curve is also called the saturation or equilibrium curve since the substance is at saturation and in equilibrium between the liquid and gas phases if on the curve.
The vapor pressure curves for commonly pumped cryogenic liquids are provided in paragraph 3. This boiling usually starts on a surface in the liquid such as a pump housing wall, cylinder or impeller or some impurity particle such as a piece of frozen carbon dioxide in the liquid.
In a cryogenic pumping system, the fluid being pumped is almost always very near its vapor pressure curve as it enters the suction port of the pump, where the pressure is at its lowest point. If the pressure is too low for the temperature of the liquid at that point, small bubbles will form at that location. The bubbles occupy more volume than the liquid from which they formed; this transient condition causes the pressure to rise again, thus causing some of the bubbles to collapse back into liquid.
This sequence of events is called cavi- tation. Cavitation has two effects on a pump: One, the collapse of the bubbles causes shock waves to develop which can damage the pump with pitting and erosion. Two, the bubbles being gas cannot be pumped. If a sufficient number of them exist, the pump will cease to operate correctly and flow through the pump will stop or be significantly reduced.
Cavitation can be avoided or corrected by either increasing the pressure at the supply source thereby in- creasing subcooling and getting farther from the vapor pressure curve or by increasing the return line flow if applicable which will lower the liquid temperature at the pump suction due to the increased flow rate lower heat leak per unit of liquid. NPSH can be defined as the difference between the actual pressure and the vapor pressure of the liquid at the pump suction port.
The larger the difference, the more NPSH or subcooling exists. Therefore, if sufficient time is allowed to elapse, the liquid in the tank will warm up to the temperature required to be on the vapor pressure curve — at which point the liquid in the vessel will begin to boil.
Since the pres- sure at the pump suction must be lower than the pressure in the vessel if there is no static head in order to cause liquid flow, it is impossible to pump a liquid that is saturated in the vessel. To achieve prime and to prevent cavitation, some NPSH must be provided to the pump. The amount of min- imum NPSH varies with the size, type and make of pump, and is generally indicated on the nameplate.
The artificial pressure must be maintained throughout the pumping cycle to insure proper and efficient pump operation. Should this occur it will become necessary to stop pumping operations, vent the supply vessel to atmospheric pressure and allow it to come to equilibrium, and restart the pump cycle again with renewed subcooling in the vessel.
Figure Overview of horizontal version top , vertical version bottom 1 Drive unit 3 Base frame 2 Drive mechanism Warm end 4 Cold end. Intended use The purpose of an ACD reciprocating pump is to transfer a cryogenic liquid from a source of supply to a re- ceiving vessel or system. A reciprocating type pump is generally chosen over other types if the desired flow rate is relatively low while the pressure rise or head is relatively high.
Reciprocating pumps, being a posi- tive displacement type, are able to produce very high discharge pressures with good efficiency and safety. ACD reciprocating pumps are generally driven by an electric motor or diesel engine that is connected to the pump through a speed reducing device such as a gearbox or belt drive. The electric motor may also have a speed controller VFD. Figure depicts a single-cylinder horizontal pump on top and a single cylinder vertical pump on bottom.
Other models may have multiple cylinders for higher flow applications. See Module 12, Appendix A for the standard scope of supply for the specific model in question. If the pump drive system includes a belt drive, ACD provides guards for the belts and pulleys or sprockets. Integration into the control system The pump assembly is intended for use within a system. It does not, in some cases, have its own control system or an autonomous emergency shutdown function. See also Section 2. Basic description The pump is a single- or multiple-cylinder reciprocating pump used to convey liquefied gases at high pres- sures and low operating temperatures.
In the cold end liquid is drawn in by the backward stroke of the piston and brought to pressure and pumped to the pressure line during the forward stroke.
An ACD reciprocating pump is normally driven by an electric motor. Depending on the application, the pump may be driven by a diesel engine, hydraulic motor, or by an electric motor through a speed-decreasing belt or gear drive system.
The belt system generally consists of several V-belts and pulleys, although some units use timing belts and sprockets. Some hydraulic motor drive the pump directly through a coupling. Figure depicts an electric motor item 1 driven vertical type pump left and a horizontal pump right. Belt guard The belt guard Figure , item 2, right or the cover plate Figure , item 2, left , protects the belt drive of the drive unit from dirt and excessive moisture.
The crosshead sleeve is generally a dry-lubricated type requiring no external lubrica- tion. The crosshead mounts the drive end of the cold end piston rod. Depending on the specific pump model, the drive mechanism may have grease-lubricated, oil splash lubri- cated, or pressurized oil lubricated anti-friction bearings. In the last case, the pump assembly may include a separate lubricating oil system lube pack consisting of an electric motor driven oil pump, an oil sump, and appropriate controls and safety devices all assembled and plumbed to the reciprocating pump.
Otherwise, the pressurized lube system will include an internally mounted oil pump that is driven by the pump shaft. If the pump is to be used in liquid oxygen service, the bearings are lubricated with an oxygen compatible lubricant. Functional description The cold end of a reciprocating pump consists of a piston rod running in a cylinder sleeve that is mounted in a housing.
The piston rod is driven by the crosshead in the warm end. At the other end of the rod is the piston area in which rings ride in circumferential grooves to effect a seal between the piston and the cylinder sleeve. At the far end of the cylinder sleeve a suction valve is installed; this design allows an almost straight-through flow during the suction stroke for minimum NPSP requirements. On the side of the discharge housing near the suction valve, and slightly beyond the end of the piston stroke, is the discharge valve which is a spring loaded ball type.
The discharge valve opens any time the cylinder internal pressure is higher than the system pressure on the downstream side. The cold end is designed with a relatively long housing and piston rod in order to provide thermal insulation to both the liquid being pumped to keep heat out and to the packing at the drive end to keep the packing warm.
Both housing and piston rod are fabricated from stainless steels both for strength at operating tem- peratures and for its relatively poor thermal conductance. Several specific hazardous areas exist in the installation of any pump in cryogenic liquid service. Any cryogenic relief valve discharge area is hazardous if personnel can be ex- posed to liquid or cold gas in the event of a discharge from the relief valve.
Uninsulated lines at pump suction and discharge, and the pump housing itself, may be cold enough to cause condensation liquefaction of air on the outer surfaces. Any combustible or flammable material in or near this condensate will have a greatly reduced flash point temperature.
For this reason the areas surrounding the pump and its uninsulated areas of piping should be very clean and the surface should not be flammable for example, no asphalt. This condensate is most noticeable in liquid nitrogen service due to its temperature frequently being below the condensation point of air. If a cryogenic valve has leakage at the packing, the valve may become frozen in place and inoperable until the valve is warmed to a point above freezing.
In addition, the cryogenic fluid is dangerous see paragraph 2. Interface description Interfaces include the suction and discharge ports, electrical connections to the motor, and purge gas con- nections if applicable. On most ACD reciprocating pumps, these interfaces are fittings matching standards as shown on the applicable installation drawing.
Gaskets generally are not required unless the pump includes a centrifugal boost pump at the suction. Any loads imposed on the pump housing by the attached piping lines must be within the limitations shown on the installation drawing. Do not exceed allowable torque when attaching pipe fittings to these ports. Terminal boxes Figure are located on the electric motor. If no options are installed, only one terminal box will be installed.
If the pump includes a purge system, the installation must include a source of purge gas supply connected to the purge system inlet. The purge gas composition, pressure, and flow capability must meet the requirements as shown in the literature accompanying the purge system.
The installation and commissioning are usually carried out by the operator or through an authorized organization. Therefore, the instructions listed below must always be considered. Danger to life posed by overhead loads! Loads can pivot out and fall down during lifting processes. This can result in serious injuries or even death. Risk of injury posed by falling or tilting packaging pieces! Packaging pieces can have an off-center center of gravity. With incorrect orientation of the lifting gear, the packaging piece can tilt and fall.
Serious injuries can be caused by falling or tilting packaging pieces. Observe markings and information on center of gravity on the packaging pieces.
If necessary, change the adjustment of the lifting gear or hook location. Risk of injury posed by pivoting out transport piece! During transport with a crane, the transport piece can pivot out and cause serious injuries and significant property damage. Property damage caused by improper transport! During improper transport, transport pieces can fall or collapse. Significant property damage can occur. Claim any deficiency as soon as it is recognized. Damage compensation claims can only be made within the valid claim deadlines.
For transport The individual packaging pieces are to be packed according to the expected transport conditions. Only envi- ronmentally safe materials may be used for packaging. The packaging should protect the individual components from transport damage, corrosion and other dam- age up until they are assembled. Consequently, do not destroy the packaging and only remove it right before assembly. Handling of packaging materials Dispose of packaging material in accordance with the legal provisions of local regulations.
Hazard to the environment posed by incorrect disposal! Packaging materials are valuable raw materials and in many cases can be reused or usefully processed and recycled. Improper disposal of packaging materials can cause environmental hazards. If necessary, commission a specialist with disposal. Lifting points The eyebolts are used for lifting the pump. In case of a skid, the eyebolts to be used as lift devices are screwed to the base frame and serve for lifting of the pump.
If necessary refresh or renew the preservation. See paragraph 2. Danger due to liquefied gases and oxygen deficient atmosphere! Risk of injury from cryogenic surfaces! Risk of injury due to improper installation and initial startup! During installation and initial start-up of a pump assembly, special safety instructions and precautions apply in addition to those provided elsewhere in this manual.
Improper installation and initial startup can lead to serious injuries and significant property damage. Components and tools lying loosely on or around each other can cause accidents.
Lifting eyes on the pump or drive mechanism if provided are not to be used for lifting the entire assembly. Specific lifting instructions are provided in Module 12, Appendix B. If the pump and related system are intended to contain liquid oxygen, special cleanliness is required; see paragraph 2. Maintain prescribed screw-tightening sequences and torques. For a safe installation, only personnel qualified in the various trades welding, brazing, pipefitting, electrical, and inspection , using proper tools, should be authorized to per- form the installation tasks.
Comply with all local codes that apply and have jurisdiction over the various as- pects of the pump installation. Fully comply with any safety requirements noted on the installation draw- ing Appendix B. The pump must be located outdoors. Protection from rain or snow will increase pump reliability and availability. Ventilation must not be impaired. There must be adequate es- cape routes and free access to first aid and fire protection equipment.
A raised concrete pad should be provided upon which the pump assembly is to be mounted. During operation and after shutdown, a large quantity of water will be present due to melt- ing of frost and ice from pump and piping. A raised pad will ensure that this water will drain away from pump at all times. The pad must be level within 0. The ambient air in which the pump is to be installed must be non-corrosive to pump as- sembly materials.
Salt air or salt water spray are particularly to be avoided. The power supply must be adequate for the intended service of the pump assembly. If the motor has a standard across-the-line motor starter, the power supply must be capable of momentarily supplying cur- rent six 6 times FLA in order to start the motor.
A soft start or VFD controlled motor does not have this last requirement. For best operation, the pump should be located as horizontally close as possible to the liquid supply source and vertically as far below it as possible. This horizontal lo- cation will provide the shortest and straightest suction piping which minimizes heat leak heat gain from surrounding atmosphere and friction losses while the vertical location will provide the greatest possible static head to the pump suction for lowest NPSH see Module 3.
If the pump is to be connected to a liquid supply port on a storage tank, best results will be obtained if the port selected is dedicated to the pump suction with no other services or duties connected. The site must be clean with no loose debris, trash, garbage, or other material not necessary to the safe installation and operation of the pump within 2 meters. The site should either be paved with concrete or covered in clean gravel or crushed rock. If the pump is intended to be placed in liquid oxygen service, no flammable materials should be stored or used within 20 meters of the pump and the site near the pump must not be paved with asphalt or any other combustible material.
For successful operation of the pump, the installer must comply with the guidelines listed below. The suction piping design and installation is of paramount importance to the operation of the pump, especially if the pump does not include a sump. Because the liquid be- ing pumped is extremely cold, and must remain so in order to successfully pump it, every means possible to limit heat gain into the liquid flowing to the pump suction and maintain sub- cooling see Module 3 must be taken.
Gas and liquid traps must be avoided by designing the suction piping to have a continuous slope downwards towards the pump suction. The use of tees, elbows, and other fittings must be minimized since they cause relatively high head loss; tees are especially unsuitable because they automatically cause a gas or liquid trap in addition to the head loss.
The line must be sized accurately for the design flow; if it is too small, the head loss will be excessive and if too large the dwell time for the liquid will be greater than ne- cessary, causing excessive heat leak.
The line must be adequately supported and considera- tion must be given to the thermal loads that will be imposed as the line cools from ambient tem- perature down to operating temperature. If a flexible hose section is utilized as recommended see Flange loads and piping alignment below , it must incorporate a smooth bore lining fabri- cated from TFE hose that runs the full length of the section in order to maintain NPSH.
If con- necting to a storage tank, a dedicated liquid supply port should be used see 6. This return line acts as a re- circulation line, allowing pump cooldown and filling of the sump if included without flow through the discharge for easier priming.
This piping should be designed similar to the suction piping with a continuous slope upwards from the pump back to the tank with no liquid or gas traps and preferably with a flexible hose section similar to that discussed above for the suction line.
It is highly recommended that the piping connecting to the pump suction and vapor return ports incorporate short flexible hose sections immediately ad- jacent to the pump ports. These flexible hose sections will decouple the pump from the piping so that no piping loads will be placed on the pump flanges or ports and simultaneously prevent pump vibrations from entering the rigid piping systems.
If it is not possible to utilize flexible hose sections, the pipe flanges or fittings that mate to the pump flanges or ports must be aligned both with regard to centerline and to parallelism. Loads must not exceed those shown on the installation drawing provided in Appendix B. The suction line must be insulated to the maximum extent possible. The line must be insulated along its entire length including all valves and connections. Insulation of the pump housing if not vacuum jacketed by ACD is not necessary although some benefit may be gained by insulating the pump suction flange or port.
Insulation absolutely must include vapor barriers to prevent the ingress of moisture which will destroy the effectiveness of the insulation. The quality k factor of the insulation cannot be overemphasized; vacuum jacketing for the suc- tion line will provide the best operation but if it is not chosen, a minimum of 8 cm fiberglass insu- lation thickness with vapor barrier and jacketing should be used.
Suction line isolation valves, in addition to being constructed and cleaned for cryogen- ic service, must be selected for minimum head loss maximum Cv. The best valves are full bore ball or gate types.
This valve is never to be used for throttling flow. Only one valve should be installed in the line, as close to the liquid supply port as possible. Only one valve, similar in design to the suction line isolation valve, should be incorporated into the return line if installed.
A pump discharge isolation valve suitable for the high pressure should be provided in the dis- charge piping. It must also be designed and constructed for cryogenic duty. Any piping line or pump that can be isolated by valves with liquid still present must have at least one relief valve incorporated to prevent catastrophic overpressure as the liq- uid boils off into gas. The relief valve should be installed on the pump discharge piping where the tee causes minimal flow disruption and set at a pressure that will protect the pump housing and all affected piping.
Capacity of the relief valve only needs to accommodate the rate of boi- loff; thus the relief valve may be relatively small in size. If required, an additional relief valve of adequate capacity should be installed on the pump discharge to protect from overpressure dur- ing operation. Covers are provided for the suction and discharge ports on the pump as well as any other fluid connections as applicable. Covers must also be used on all piping. Covers should not be removed until immediately prior to connection of piping to pump to maintain cleanliness of the pump and system.
Prior to connection, visually check ports and pipes to veri- fy that there are no obstructions or foreign material desiccant bags, for example. After all piping is complete and connected, the system should be purged with dry nitrogen gas to ensure that moisture from ambient air is removed.
Wiring and cabling must be selected for adequate size and insulation based on the anticipated current load and allowable temperature rise. Comply with all local and regional applicable codes. Do not tighten bolts fastening pump to pad or skid to final torque until the first time pump has been cooled to operating temperature. This will minimize stresses on piping and pump housing.
After the installation is mechanically and electrically complete, the following checks and inspections must be performed prior to initial startup: 1. Inspect system. Check all piping and connections for correct connection and tightness. Pressure test. No external leakage or structural deformities are allowed. ACD supplied components are factory certified and do not require pressure testing. Auxiliary equipment. If a separate lubricating pump and system is included in the pump assembly, verify that it is ready to operate with proper lubricating oil installed and all subsystems complete.
If a belt drive is included, verify that the belt is properly aligned and tensioned. In either case, verify that all covers and guards are properly reinstalled. If a boost pump is provided for the reciprocating pump suction, verify that it is ready to operate.
Perform an inspection and operate it in accordance with its manual. Pump rotation. The driver should be energized momentarily to check for proper direction of rotation. Some reciprocating pumps are able to operate in either direction, so rotation direction may not be of conse- quence. See Module 12 for applicability. Cold check. After successfully performing the pressure test preceding, the pump and its piping should be cooled down to operating temperature by opening the suction, discharge, and return valves and inspecting for any deformation due to contraction of the piping.
Again, there must be no external leakage. Risk of injury posed by cryogenic and hot surfaces! Danger posed by liquefied gases and liquid jet emerging under high pressure! The reciprocating pump is installed into a complete pumping installation that incorporates all the various controls into one system.
When incorporating the pumping unit into a complete system with separate automatic controls, care must be taken to insure that all the local regulations and standards are followed. The control logic must be configured so that no hazardous situation can arise due to incorrect operation and that an automatic operational sequence is installed that prevents human error.
Actions and observations The following personnel qualification and protective equipment are absolutely necessary for work with and in the vicinity of the pump:. Certain actions and observations should be taken by the operator during pump operation to ensure safe con- ditions are maintained. These actions and observations include:.
Frequently observe the pump and drive mechanism for proper operation. Check for any unusual noise, vibration, excessive heat at bearings, or any other condition that is not normal. Check for leaks at all fittings, connections, and seals. Verify that pump is well primed with normal discharge pressure and normal valve settings. Even though every precaution has been taken to protect personnel from moving parts, the operator must ensure that all personnel in the area surrounding an operating pump are aware of the potential dangers of rotating equipment.
The operator must ensure that all personnel in the area surrounding an operating pump are aware that the exposed pipe and pump surfaces are extremely cold and may cause injury if touched. In addition, if air condensation occurs see Section 4. No maintenance should be performed while the pump is operating. All maintenance is to be performed when the pump and related piping have been depressurized, warmed to ambient tempera- ture, and energy source s locked out.
The operator should maintain logs of the pump operation. Logs should include time and date of entries, pump operating data such as suction and discharge pressure, cumulative operating hours, and any other pertinent data as desired such as supply tank level and pressure, receiving system data, etc.
Verify that the supply source has sufficient liquid available to complete the antic- ipated duration of pump operation. Also verify that the liquid condition degree of subcooling, see section 3 is adequate to provide the required pump NPSH. If necessary, raise the pressure over the liquid in the supply source to temporarily increase subcooling. Verify that the vessel or system that is to receive the pumped liquid is ready to receive with valves properly aligned and sufficient capacity available.
Inspect the pump assembly to verify that pump is in operating condition. Verify that the energy source is connected or ready to be connected. Cooldown If the supply and receiver are prepared for pump operation and the pump itself is also prepared, initiate cool- down by opening the suction, return line, and discharge vent bleed valves. The discharge valve should remain closed unless a discharge check valve is included in the system.
Liquid will begin to flow through the stationary pump to bring piping and pump down to operating temperature. The following general procedure is to be used:.
Check for prime. The pump is momentarily started and discharge pressure is observed. If an appro- priate discharge pressure is observed, indicating that the pump has primed, the discharge valve can be opened while simultaneously closing the discharge vent bleed valve. If prime is not achieved, the pump is to be stopped and cooldown allowed to continue. Adjustment of pressure in supply source may be required to increase sub-cooling.
Normal operation. If prime has been achieved, adjust return line valves as necessary to maintain pump prime.
While operating, the pump assembly is to be checked frequently for continued normal operation. If abnormalities are observed that cannot be removed by valve adjustment, the pump should be stopped and the abnormality investigated.
Otherwise, normal operation may continue until the pumping operation is complete or the operator otherwise chooses to stop operation. Pumping operation may be stopped and restarted as necessary for the particular installation. If the system includes a discharge check valve, the discharge isolation valve may remain open; otherwise, it should be shut prior to stopping the pump to prevent backflow.
The pump can remain in standby as long as the frost line on the visible portion of the piston rod s remains close within 2 cm to the normal operating position.
If the frost line approaches too closely to the drive warm end, the pump must be completely secured see Section 7. Further operation, in that case, will require preparation for startup Section 7.
Prior to and during operation, the pump and its piping system should be frequently checked for leakage. This is ascertained by observing the nature of the apparent leak. If the leak consists of a drip or running liquid, with little or no pressure behind it, that occurs at a low point in the line or on the pump housing and subsequently disap- pears as frost covers the surface, the leak is most likely air condensation, not a true leak.
Leakage at mechanical joints such as flanges and fittings, as well as at valve packing, may be repaired in place after the system is depressurized and warmed to ambient temperature. If leakage is observed at the piston rod seal, pump disassembly is required to effect repair.
While the pump is operating, the drive mechanism and motor bearings should be occasionally checked for normal operation. Depending on the drive mechanism employed, the following checks should be made: Belt drive: Observe for unusual noise or vibration.
Do not remove belt drive covers while in operation. Hydraulic motor: Observe motor and connecting hoses for proper pressure, temperature, and absence of leakage. Observe for unusual noise or vibration. Bearings motor and drive : Bearing temperatures should be checked using a surface contact thermocouple, thermistor, or RTD, or a non-contact infra-red IR temperature detector.
Temperature measurements should be made and logged soon after initial startup and at regular intervals thereafter, preferably using the same instrument, to establish normal operating temperatures and to draw attention to any trends. The pump must be incorporated in an emergency shutdown chain. The following measures pertain only to the pump and not to other components of the overall system. In the event of an emergency in which the pump must be secured as quickly as possible, the following ac- tions are to be taken in the order given as time allows: 1.
Stop pump. Close suction valve. Close discharge and return valves. Open system vent or drain valve in a safe location to relieve pressure. Remove energy source open circuit breaker, for example. Secure supply source and receiving system as time allows.
Keep persons out of the hazard zone. If necessary, take first aid measures. Inform responsible persons at the site of operation. Switch off pump assembly and secure against re-engagement. Make access routes open for rescue vehicles.
Direct rescue vehicles. After rescue measures 9. If the severity of the emergency requires, inform the appropriate authorities. Only qualified technical personnel shall be permitted to analyze and correct the cause of the emergency.
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