Flanges, blind

In accordance with hsted standards, blind flanges may be used at their pressure-temperature ratings. The minimum thickness of nonstandard bhnd flanges shall be the same as for a bolted flat cover, in accordance with the rules of the ASME Boiler and Pressure Vessel Code, Sec. T11. 

Operational blanks shall be of the same thickness as blind flanges or may be calculated by the following formula (use consistent units) ... 

Unstayed flat heads and covers can be designed by very specific rules and formulas given in this subsection. The stresses caused by pressure on these members are bending stresses, and the formulas include an allowance for additional edge moments induced when the head, cover, or blind flange is attached By bolts. Rules are provided for quick-opening closures because of the risk of incomplete attachment or opening while the vessel is pressurized. Rules for braced and stayed surfaces are also provided. 

Elimination of the position of maintenance supervisor on the second and third shifts (this was a direct cause of the failure to install the blind flange)... 

AS—Air Supply BD—Blowdown BF—Blind Flange CBD—Continuous Blowdown CD—Closed Drain CH-O—Chain Operated CSO—Car Seal Open CSC—Car Seal Closed DC—Drain Connection EBD—Emerg. Blowdown Valve ESD—Emerg. Shutdown FC—Fail Closed FO—Fail Open HC—Hose Connection IBD—Intermittent Blowdown LO—Lock Open ML—Manual Loading NC—Normally Closed NO—Normally Open OD—Open Drain... 

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

Blind flanges (blank flanges) are flat plates, used to blank off flange connections, and as covers for manholes and inspection ports. 

For blind flanges and blanks, T shall be % of the flange thickness. 

In such huge tanks, since the area to be rubber lined is more than 2000 sq meter including pipes and fittings, manhole flanges and blind flanges and other accessories, the total area is sand blasted, primer... 

Availability of extra blind flanges for hot water curing... 

Always consider that, in cryogenic applications the risk exists that moisture in the air can cause the valve to freeze up around the seat area when the valve shows the smallest leak. This can have the same effect as welding the disc down on the seat, preventing the valve from opening so that it acts like a blind flange (see Chapter 11 for details). 

Below -70°C and thermal expansion Typical applications here are LNG, LIN and LOX. Here again, we must avoid the risk of freezing, but in this case we also need to consider repeatable tightness therefore, high-performance, soft-seated spring valves should be used. A metal seat may leak prematurely, freeze up and start acting like a blind flange. 

There are two basic test configurations. The first is a blind flange setup where the sample is clamped between a glass tube containing the liquid and a temperature-controlled heater. In this test, two samples can be tested under identical conditions. The second is a retaining cup clamped onto the sample. Figure 9.7 illustrates the two types of test cells. 

At this section of the plant in the past, chemical process operators (not maintenance mechanics) handled the tank-filling step in the hydrotest process. Operators would typically drape a fire hose into an oversize roof nozzle and fill the tank from the nearest hydrant. In this case, it was reported the two mechanics asked their maintenance supervisor if they could connect the hose to a flanged lower-valved nozzle on the tank. The supervisor remembers requesting the mechanics to roll a blind flange at the top for venting purposes if they used the lower nozzle for filling. There must have been a miscommunication. Obviously the mechanics failed to understand the dynamics of the filling operation when they chose to open only the two 1/2-inch top vents. 

Chemical resistance test for rubber linings by Atlas blind flange test Determination of effects of liquid chemicals on plastics Determination of environmental stress cracking (ESC) by the bent strip method... 

Roberts cell blind flange test for linings exposed to high temperatures and pressures... 

Established Phillips corporate safety procedures and standard industry practice require backup protection in the form of a double valve or blind flange insert whenever a process... 

The immediate cause of the leak was that a process valve was opened by mistake while the line was open. The valve was open to the atmosphere without a second line of defense such as another valve or a blind flange. 

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