Vessels manhole

Hole/B Cap Diameter, inches Deck Material/Thickness Valve/B Cap Material Hardware Material Support Material/Thickness Total Corrosion Allowance Vessel Manhole I.D., inches... 

Vessel Manhole Identical to a nozzle except it does not bolt to piping and it has a cover plate (or blind flange), which is bolted to the flange. When unbolted it allows access to the inside of the vessel. Generally 18 in. or larger in size. 

The mesh pad shall be in one piece or sectional as required for insertion through the vessel manway. Each pad section shall be removable through the vessel manhole. 

Chlorine is stored and transported as a Hquefied gas in cylinders of 45.4-kg or 68-kg capacity that are under pressure and equipped with fusible-plug rehef devices. Quantities in the range of 15 to 90 t are transported in tank cars having special angle valves on the manhole cover on top of the vessel. Tank barges of the open-hopper type having several cylindrical uninsulated pressure vessels are used for amounts ranging from 600 to 1200 t. Road tankers are used for capacities of 15 to 20 t. 

The vessel cover is free of drive components, allowing space for additional process nozzles, manholes, explosion venting, etc., as well as a temperatrrre lance for direct, continrrorrs prodrrct-temperatrrre... 

Historical data on similar vessels and fractionation towers can best be used by correlating the costs of this equipment vs. weight. Many methods can be found in the literature for estimating the weight and costs of vessels and fractionators (References 8. 9, 10, and 11). Make sure the estimated weight is complete including skirt, ladders and platfonns, special internals, nozzles, and manholes. 

If vessels are open but entry is not yet authorized, the manhole should be covered by a barrier. Do not rely on contractors reading rules. Explain the mles to them. 

When a plant was being leak-tested with nitrogen after a shutdown, a leak was found on a manhole joint on the side of a vessel. The pressure was blown off, and a fitter was asked to remake the... 

On the day of the accident, an instrument meehanic entered a 2-m tank to adjust the instruments. There was no written entry permit because the people concerned believed, mistakenly, that entry permits were not required in a new plant until water or process fluids had been introdueed. Although the tank was only 6 ft tall and had an open manhole at the top, the meehanic collapsed. An engineer arrived at the vessel about five minutes later to see how the Job was getting on. He saw the mechanic lying on the bottom, climbed in to rescue him, and was overcome as soon as he bent down. 

The material of constmction of the vessels D and C was not suited for use under low temperature conditions. Vessels A and B were, however, suitable. The location of initial brittle fracture in vessel C was the weld seam near the manhole. Vessel D probably failed as a result of impact from a fragment from vessel C. 

Flat plates are used as covers for manholes, as blind flanges, and for the ends of small diameter and low pressure vessels. 

Flanged joints are used for connecting pipes and instruments to vessels, for manhole covers, and for removable vessel heads when ease of access is required. Flanges may also be used on the vessel body, when it is necessary to divide the vessel into sections for transport or maintenance. Flanged joints are also used to connect pipes to other equipment, such as pumps and valves. Screwed joints are often used for small-diameter pipe connections, below 40 mm. Flanged joints are also used for connecting pipe sections where ease of assembly and dismantling is required for maintenance, but pipework will normally be welded to reduce costs. 

The traditional unpredictably violent nature of the Skraup reaction (preparation of quinoline and derivatives by treating anilines with glycerol, sulfuric acid and an oxidant, usually nitrobenzene) is attributed to lack of stirring and adequate temperature control in many published descriptions [1], A reaction on 450 1 scale, in which sulfuric acid was added to a stirred mixture of aniline, glycerol, nitrobenzene, ferrous sulfate and water, went out of control soon after the addition. A 150 mm rupture disk blew out first, followed by the manhole cover of the vessel. The violent reaction was attributed to doubling the scale of the reaction, an unusually high ambient temperature (reaction contents at 32°C) and the accidental addition of excess acid. Experiment showed that a critical temperature of 120°C was attained immediately on addition of excess acid under these conditions [2],... 

In completely enclosed vessels, there must be at least one manhole of size not less than 18" x 16" if it is in rectangular shape. If the manhole is in circular shape, the diameter of the same should not be less than 18" with an additional branch pipe fitting of 3" diameter. 

A schematic of a trickle bed reactor is shown in Fig. 19-40. The reactor is a high-pressure vessel equipped with a drain and a manhole for vessel entry. Typical vessel diameters may range from 3 to 30 ft with height from 6 to 100 ft. The liquid enters the reactor and is... 

In addition to the ventilation duct the lid is equipped with two feed pipes, one for acids, (6), and one for the substance to be nitrated, (7), a thermometer sleeve (8), a delivery pipe for compressed air (9) and a pipe (10), reaching down to the bottom, for discharging the nitrator contents by means of compressed air. It is essential to furnish the lid with a manhole (II). During nitration, the manhole opening is closed by a thin sheet of aluminium, which at the same time plays the role of a safety valve in case the pressure should rise inside the vessel. 

The lid of the sulphonator has an exit for the exhaust pipe, two inlets for introducing the reactants, a manhole, an inlet and outlet for steam passed through the coil and a thermometer hole. In addition to this, the lid is equipped with a sight glass and four handles to open the sulphonator. The heating coil is not shown. This vessel is discharged at the bottom. 

Numerous articles have been published which give methods for obtaining vessel costs based on estimates of costs for the individual components, such as for materials, labor, nozzles, manholes, and overhead related to fabrication, to arrive at an estimated cost (f.o.b) at the fabricator s shop. Final installed cost can be obtained by applying factors to account for freight, labor, materials, engineering, and overhead related to getting the unit to the plant and installing... 

Costs for vessel (January, 1990—Including nozzles, manholes, and saddle or skirt but no special internals such as trays or agitators) as dollars per pound of weight of fabricated unit f.o.b. with carbon steel as the cost basis = 80O ) 0-34 where W is the total weight in pounds (applicable in Wv range of 800 lb to 100,000 lb). 

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