| INTRODUCTION: world industries has a lot of | | | | have more safety and prevent from unintentional |
| high-pressure plunger reciprocating pumps. | | | | mistake by operators of the pump above in the |
| According to research done, there are also a | | | | industries, we consider timer delay on in (on |
| considerable number of the pumps above in world | | | | button) of the electrical motor so that as soon as |
| Ministry of Oil and other industries. Energy | | | | the operators presses on button to start pump, |
| transfer to the fluid of the aforesaid pumps is | | | | xcv will be immediately opened, and pump |
| done periodically while the moving force is supplied | | | | pressure is dropped, if existed (i.e. the related |
| by powerful electrical motor. Revolution of | | | | manual valve is closed), will be occurred, and then |
| electrical motor is transferred to the crankcase | | | | electrical motor and pump will be in service. We |
| after being decreased in the gear box. Then, the | | | | also consider timer delay off in off button, so that |
| rotary Revolution of the crankshaft is changed | | | | similar operation can be done at the time of pump |
| into reciprocating one in plungers Returning of the | | | | stopping. After permanently installing the plc |
| plunger through the inside of cylinder makes a | | | | system above, trip of the pump under load will be |
| vacuum condition and consequently ,the liquid | | | | prevented (high pressure), whose consequences |
| enters the cylinder through a suction check valve | | | | include, increased productivity, preventing from |
| and the movement of the plunger makes the | | | | the above-mentioned damages to pump and |
| suction close completely which discharge opens | | | | electrical motors, No need for expensive spare |
| and the liquid is transferred towards a Discharge | | | | parts. Preventing from severe damages of |
| vessel .there are two main technical rules in | | | | plunger to seals which causes frequent leakages |
| plunger pumps: 1-they must never be started | | | | of the pumped liquid(that are economically a lot of |
| while the discharge valve is close. 2-they must | | | | expenditure for buying and transporting the |
| never be shut down while having operated with | | | | liquid).for example crankshaft of plunger pumps |
| an operational pressure. Considering that the most | | | | for injecting glycol weighs 895 kilogram, |
| permits of repairing activities have been issued for | | | | power=75 KW, Revolution=1450 RPM , weight of |
| the pumps above (due their high output | | | | motor=533 KG, 380 volt,144 amp and 3 phase |
| pressures), and that they have expensive mainly | | | | whose rotation speed is 68 revolutions per minute |
| foreign parts, it requires a special attention to | | | | (rpm). At the time of emergency stopping, the |
| starting, stopping, and maintenance of the pumps. | | | | whole of a 7000-kilogram equipment will be |
| | | | | stopped in an instant, due to lack of the system |
| DISCUSSION: The pumps above have a standard | | | | above in plunger pumps. Above pumps Have 3 |
| safe instruction for starting and stopping, in which | | | | reciprocating plungers and move in 3 cylinders |
| a manual valve is considered beside the pump by | | | | separately in each pump .that plungers function |
| the pump designer and manufacturer. This valve, | | | | are periodic and transfer extremely energy to |
| indeed, acts as a connector between input and | | | | liquid(DEA glycol).we consider And use analysis of |
| output surge tank, which after opening the valve | | | | limited element on moment. All of once a one of |
| above, the pump pressure will reduce from high | | | | plungers move forward in to cylinder and that |
| pressure to approximately suction pressure, | | | | cause transfer pressure Energy to liquid(suction is |
| consequently being balanced. According to the | | | | full close and discharge is full open and pressure is |
| manufacturer's recommends, the manual | | | | high in cylinder).another plunger return inside |
| connecting valve should be open at the time of | | | | cylinder and Intake fluid (suction is full open and |
| starting or stopping; and the pump specialists are | | | | discharge is full close).the third plunger is between |
| very sensitive to pressure unbalance at the time | | | | two operation in above. In emergency shut down |
| of starting and stopping, due to awareness of its | | | | (Suddenly stopped) very quickly all thinks stopped. |
| destructive consequences and irreparable | | | | In fact that plunger go forward in cylinder can not |
| damages on the pump and electrical motor parts. | | | | do anything and Immediately stopped |
| But in some causes, the plunger pumps above will | | | | hard.because resistance high pressure and plunger |
| be out of service in unwanted manner, including | | | | don't energy for continue ,it can not move but |
| Emergency shut down (due to such factors as | | | | two plungers don't have problem for continue |
| high temperature oil alarm and low pressure oil | | | | move. But that is critical point for crank shaft and |
| alarm,…). When operating the switches above, | | | | what took place is completely unexpected and |
| the pump will be out of service in very high | | | | crank shaft put under torque (angular |
| pressure with sudden stoppage. According to the | | | | momentum) All technical expert Understand That |
| investigations conducted, most of repairs and | | | | torque is very heavy and the tragic |
| failures in the pumps which have the most | | | | consequences of that operation many years in |
| unwanted disabling, including, Broken crankshaft in | | | | world industries . all pumps have a leakage liquid |
| several stages, Broken plungers or deviation from | | | | permanent. cost of liquid (buying and transferring) |
| standard path, crushed moving parts such as | | | | is high in price. we use a new packing(high |
| bearings, couplings and gears, Continual abnormal | | | | technology and self lubricate). don't need a oil for |
| sounds, Repetitive leakages from fluid seals and | | | | lubrication. Collect all leakage from every side |
| packing, Broken glands and internal rings. | | | | Glands , Plungers and Air sealing line is simple and |
| | | | | directly transfer to nearest sump in unit. Another |
| METHOD&RESULT: The existing pump | | | | suggestion: Many pumps have a PCV valve in |
| technology is related to nearly 3 decades ago. So | | | | discharge line for control extra pressure and we |
| the considerable changes will be created in amount | | | | can use that PCV .but that need a some |
| of productivity and increase in maintenance of the | | | | mutations. as an example must be replacement |
| pumps above through designing and installing a | | | | PCV suction line to before check valve and add |
| PLC system .one xcv valve is installed parallel to | | | | ON/OFF mode to percentage mode. |
| the manual valve balancing output and input | | | | |
| pressure of the pumps, which will transfer all shut | | | | CONCLUSION: I expect to install the PLC systems |
| down signals of the pump to the xcv above. | | | | above or do mutations on pcv (control extra |
| After the xcv is opened, instantaneous pressure | | | | pressure) and use new technology packing |
| discharge balancing will be done; and then | | | | (sealtek brand) on all pumps available in the oil, |
| according to the manufacturer offer, the electrical | | | | gas, petrochemical and other industries world, |
| motor will continue several seconds to move in a | | | | which can be examined and considered in the |
| descending manner, normal safe manner around | | | | technology of high-pressure plunger pumps in the |
| the pressure discharge will be done;, normal safe | | | | all factories manufacturing pump. |
| manner around the direction of total stop; and the | | | | ACKNOWLEDGEMENT: Special grateful to the all |
| pump will consequently continue to move with | | | | persons to teach ,training me and my technical |
| several reciprocating cycles of the plunger (having | | | | colleagues that they prove by experience full of |
| descending rate) and then will be stopped. The | | | | science. |
| pump starting and stopping will be done by(on | | | | |
| off) buttons of the electrical motor. Therefore, to | | | | Warmly thank, Any questions? |