Seal oil systems

Pressure gauges should be provided at the diseharge of the pumps, the bearing header, the eontrol oil line, and the seal oil system. Eaeh atmospherie oil drain line should be equipped with steel nonrestrietive bull s-eye-type flow indieators positioned for viewing through the side. Viewports in oil lines ean be very useful in providing a visual eheek for oil eontamination. 

Mechanical analysis. This includes detailed analysis of the bearing temperatures, lube, and seal oil systems and other mechanical subsystems. 

Lubricating and seal oil systems cleaned Instrumentation and controls checked Preliminary operation of lubricating and seal oil systems Operation with air Vacuum Equipment Alignment run-in testing Pumps... 

Probably the biggest single advantage of dry gas seals is getting rid of the seat oil. The seal oil system, even when part of a combined lube and seal system, is a complex assembly. With the dry gas seal, the lubrication oil system is all that is needed to service the compressor train bearings and, on turbine driven units, to also supply turbine control oil. As. ui aside, it makes feasible the dream long held by the compressor vendor of having a standardized lube system line. 

Figure 8 4. Lube oil block diagram used for a compressor lube system with a control system and a seal oil system.

Figure 12-50C. The seal oil system supplies filtered oil to the liquid film rings or to mechanical-type seals at the correct pressure and temperature. The system is basically designed in accordance with API 614 and is suitable for continuous compressor operation. (Used by permission Bui. PROM 526/I-5/95-II. Nuovo Pignone, Florence, Italy New York Los Angeles and Houston, Texas. All rights reserved.)...

Alloy 20 or Monel pump material and dual mechanical seals should be used with a pressurized seal oil system. 

The result of the oil ingress was an 18-month shutdown while PSP valve and filter assemblies were removed and new filters were fitted. The pump seal oil systems were modified to prevent any further possibility of oil ingress, and alarm and trip systems were added to prevent blockage of the pump filters in order to protect the subassembly filters. 

For lube and seal oil systems, provision of interlocks to prevent startup of the machine unless the oil system is operating backup systems. Alarms (or shutdowns) in case of high bearing temperature and low oil flow. 

The seal oil system supplies oil to the hydraulic seals of the compressor, whidi are located at the outer ends of the shaft, at a constant temperature and pressure, nie oil escaping the low-pressure side of the seal returns to the reservoir and is recirculated. Oil escaping through the high-pressure side passes through sour oil traps to the seal oil degassing tank. ... 

There are two types of seal oil systems.- gravity and pressurized. The gravity-feed seal oil system reservoir is mounted above and in view of the compressor, whose elevation is set by the compressor vendor. The sour oil traps can be integral with the lube oil console skid or located on a separate skid. The pressurized seal oil system is a pump-around facility whose components are integral to the lube oil console skid or mounted on a separate d. If components are mounted on a separate skid, placement must accommodate seal oil console operation and maintenance,... 

There are a great number of lube and seal oil systems in these units. The fluid cokers may have up to three cyclones or venturis to separate the coke fines from the overhead products. Because the products leaving these units will have to be cooled, waterside problems will occur at these temperatures (formation of iron oxides and hardness deposits will require chemical treatment). The furnace itself will be steam/air decoked, but the fuel lines will have to be periodically cleaned to reduce burner fouling. 

The deposits found here are primarily inorganic and usually are iron sulfide, iron bisulfide, or iron oxides. Quite often a combination of all three is found. This can be the most fouled part of a hydrofiner, as the metals are of lower alloys and there will be very little instrumentation on these systems. One refiner found his problem when he could not close his valves to bring down the unit. Considerable iron bisulfide also may be present. The compressors will have lube and seal oil systems that will also require cleaning. 

A very important part of a cracking unit consists of the lube and seal oil systems. In addition to the pumps and boiler uses, a cracking unit will have large systems for the air compressors and cyclone separators, which these units contain. Systems of up to 6000 gal (22,710 L) are not uncommon. 

A low differential pressure or low oil pot level on the seal oil system, a low—low seal oil differential pressure or low—low seal oil pot level switch to shut down the prime mover, and an alarm to indicate that the machine has shut down. 

Mechanical seal is similar to the liquid film seal, except the clearances in it are reduced to zero. Mechanica] seal is operated at 35-50 psi above the gas pressure. Some mechanical seal use process gas as seal fluid and seal oil system can be eliminated. Liquid film seal has two sleeves, which run at close clearance to the ft. Seal oil is injected between the sleeves at 5 psi above the gas pressure. Liquid film seal requires higher seal oil circulation than the mechanical seal, [5]... 

Lubrication oil system is used to lubricate and cool the bearings at compressor, its driver, gear, and coupling. Seal oil system is used to provide seal oil for lubrication and cooling at seals. For heavily contaminated gas service, a separate lubricaiioD and seal oil system is required. 

In special applications that are potentially poisonous and explosive, the seal-oil system design may be customized with a purge-oil S5 stem that provides a buffer against the hazard and prevents leakage. Major seal vendors have seal models that will have appropriate jets and clearances for these applications. 

---