Drain line

Oil supply and drain lines shall be type 300 stainless steel. 

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. 

The preferred accumulator is the bladder type as shown in Figure 8-9. Body material should be 300 series stainless steel, in accordance with. ASTM A 240. Either a manual precharge valve or automatic charging system can be used, based primarily on the user s preference. The alternative choice is a direct contact accumulator as seen in Figure 8-10. This accumulator has several problems. The gas used to pressure the top of the oil will eventually be absorbed by the oil, which can lead to drain line foam-... 

The area below the stack and windbreaker is paved with concrete, surrounded by a 200 mm curb, and graded to a central drain point from which a drain line is routed to a manhole in a vented section of the oily water sewer. The water inlet should be sealed and the manhole should be located at least 15 m from the windbreaker. 

An incident occurred because area A foreman issued a permit for work to be done on a flow transmitter in a pipeline in area B. Area B foreman issued a permit for grinding in area B. He checked that no flammable gas was present and had the drains covered. He did not know about the work on the flowmeter. A spark set fire to a drain line on the flowmeter, which had been left open. 

In one incident, a man was draining water, through a 2-in.-diameter line, from a small distillation column rundown tank containing benzene. He left the water running for a few minutes to attend to other jobs. Either there was less water than usual or he was away longer than expected. He returned to find benzene running out of the drain line. Before he could close it, the benzene was ignited by the furnace which heated the distillation column. The operator was badly burned and died from his injuries. 

If water has to be drained regularly from liquefied flammable gases or other flashing liquids, and if a spring-loaded valve cannot be used, then a remotely operated emergency isolation valve (see Section 7.2.1) should be installed in the drain line. 

Many fires have been prevented or quickly extinguished by remotely operated emergency isolation valves. We cannot install them in the lines leading to all equipment that might leak. However, we can install them in the lines leading to equipment that, experience shows, is particularly liable to leak (for example, very hot or cold pumps or drain lines, as described in Section 7.1.2) or in lines from which, if a leak did occur, a very large quantity of material, say 50 tons or more, would be spilled (for example, the bottoms pumps or reflux pumps on large distillation columns). 

Restrict the size of the second drain valve to M in., and place it at least 1 m from the fust valve. The drain line should be robust and firmly supported. Its end should be located outside tbe shadow of the tank. 

Fit a remotely controlled emergency isolation valve (see Section 7.2.1) in the drain line. 

Some vertical drain lines in a building were no longer needed, so they were disconnected and capped but left connected to the horizontal main drain below. The caps were fixed with tape but were not made watertight as there was no way. it seemed, that water could get into them. Fifteen years later a choke developed in the main drain, water backed up into the disused legs and dripped into an electrical switch box. All power was lost, and some of the switch gear was damaged beyond repair [23]. 

A blowdown drum was taken out of service and isolated. The drain line was removed and a steam lance inserted to sweeten the tank. The condensate ran out of the same opening. 

The drain (blowdown) line on a boiler appeared to be choked. It could not be cleared by rodding (the choke was probably due to scale settling in the base of the boiler), so the maintenance foreman pushed a water hose through the drain valve and turned on the water. The choke cleared immediately, and the head of water left in the boiler pushed the hose out of the drain line and showered the foreman with hot water. Although the boiler had been shut down for 15 hours, the water was still at 80°-90°C and scalded the foreman. 

Clearing the choke should not have been attempted until the temperature of the water was below 60°C, the foreman should have worn protective clothing, and if possible a second valve should have been fitted to the end of the drain line as described in (a) above. The accumulation of scale suggests that the water treatment was not adequate [3]. 

Blowdown from the boiler(s) should always be taken to either a blowdown sump or blowdown vessel before discharging into drains. Both should be adequately sized to give cooling by dilution and be fitted with vent pipes to dissipate pressure safely. The boiler(s) should have independent drain lines for the main manually operated blowdown valve and the drains from a continuous blowdown system. Where more than one boiler is connected to either system the line should be fitted with a check or secondary valve capable of being locked. 

Most reservoirs have a capped opening for filling, an air vent, an oil level indicator or dipstick, a return line connection, a pump inlet or suction line connection, a drain line connection, and a drain plug (see Figure 40.19). 

Blowdown and heat recovery system (BDHR) flash tanks and heat exchangers are potential candidates for sludging, leading to restrictions in the drain line or heat transfer surfaces. Deposits in the BDHR heat exchanger may lead to under-deposit corrosion and leaks. 

A drain line used to remove condensate from the main steam line. Freeboard ... 

The drum filter consists of a 1 to 5 m diameter cylindrical drum that rotates while remaining partially submerged in an open-feed slurry tank. The drum surface is wrapped around tightly with the filter medium. The drum shell is divided into compartments, and drain lines are connected to the central valve system that permits either vacuum or pres-... 

Streams Medium size releases of moderate to low frequencies. Typically small diameter pipe openings that have not be adequately closed, i.e., sample or drain lines. 

Failure of a drain line connection allowed vapor release and explosion to occur. 

Precautions should be taken to avoid flashbacks. Flashbacks result from improperly mixed fuel and air, such as when the flow regulators on the instrument are improperly set or when air is drawn back through the drain line of the premix burner. Manuals supplied with the instruments when they are purchased give more detailed information on the subject of safety. 

Why must a premix burner have a drain line attached What safety hazard exists because of this drain line and how do we deal with it ... 

Auxiliary process fluid piping inclndes vent and drain lines, balance lines, product flushing lines, and lines for injection of external fluid. 

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