Rupture, disk Metal

DISK TEMP. -F RUPTURE DISK METALS DISK TEMP. °F RUPTURE DISK METALS ... 

Rupture Disks A rupture disk is a device designed to function by the bursting of a pressure-retaining disk (Fig. 26-15). This assembly consists of a thin, circular membrane usually made of metal, plastic, or graphite that is firmly clamped in a disk holder. When the process reaches the bursting pressure of the disk, the disk ruptures and releases the pressure. Rupture disks can be installed alone or in combination with other types of devices. Once blown, rupture disks do not reseat thus, the entire contents of the upstream process equipment will be vented. Rupture disks are commonly used in series (upstream) with a relief valve to prevent corrosive fluids from contacting the metal parts of the valve. In addition, this combination is a reclosing system. 

A rupture disk is a non-reclosing thin diaphragm (metal, plastic, carbon/graphite (non-metallic)) held between flanges and designed to burst at a predetermined internal pressure. Each bursting requires the installation of a new disk. It is used in corrosive service, toxic or leak-proof applications, and for required bursting pressures not easily accommodated by the conventional valve such as explosions. It is applicable to steam. 

Figure 7-8B. Standard rupture disk. A prebulged rupture disk available in a broad range of sizes, pressures, and metals. Courtesy of B.S. B. Safety Systems.

Figure 7-8F. Rupture disk (top), similar to Figure 7-8E, except a metal vacuum support is added (see Figure 7-8F(A)). By permission, Fike Metal Products Div., Fike Corporation, Blue Springs, Mo.

Figure 7-9A. Non-metal frangible disk. Ruptured disk showing complete breakout of membrane. Courtesy of Falls industries, Inc.

Figure 7-31 A. Rupture disks as sole relieving devices. By permission, Fike Metal Products DIv., Flke Corporation.

Rupture Disk/Assemblies, Cat 73-123, Fike Metal Products Corp., Blue Springs, Mo., 1973. 

Units depend on consistency with other symbols in equation, or manufacturing range for metal bursting/rupture disks, mj = spark energy, milli-joules inTyr = mass of TNT, lb... 

Runaway reactions, 405 Runaway reactions, DIERS, 521-523 Rupture, disk, 401, 418, 435, 455 Burst pressure, 456 Calculations, non-explosive, 455, 459 Code pressure levels, 410 Effects of temperature, 458 Graphite, 418-420, 424 Installation, 422, 423 Liquids, 462 Low pressure, 418, 421 Manufacturing range, 434, 456 Metal, 411 Non-fire, 465 Quick opening, 414, 415 Reverse buckling, 413 Selection features, 434... 

The pressure vessel should be lined with Hastelloy-C, stainless steel, or other metal resistant to attack by hydrogen fluoride, because the latter substance is a by-product of the reaction. The pressure vessel employed should be safe for use at 500 atm. pressure and should be equipped with a rupture disk rated at 500 atm. If the equipment available is rated for use only at lower pressure, the size of the charge should be reduced appropriately. 

Apparatus for Blasting Coal, patented by Davis et al, consists of a pressure-resistant metal tube, the end of which is sealed by a rupture disk for releasing the gas pressure at the desired value. The tube contains a chge of gas-generating expl, such as AN + starch, with a nichrome elec heater embedded in it. 

A rupture disk is a thin sheet of metal installed below the valve, intended to protect the relief valve from plugging. The rupture disk ruptures at the relief-valve-set pressure. A better approach to retard this plugging problem is to maintain a steam purge, or inert-gas bleed, below the relief valve to prevent the accumulation of solids below the valve. 

The available rupture disk (RD) materials and temperature limitations are listed in Tables 3.152 and 3.153. Their rupture tolerance (error) is 2% of set pressure, which can be up to 8,000 barg (100,000 psig). The RD in its simplest form is a metallic or graphite membrane that is held between flanges. It bursts at some predetermined pressure and relieves the pressure in the protected equipment before the system components fail. Another common use of an RD is as single use, fast-acting valves used in fire suppression systems. Table 3.152 lists some RD design variations and their features. 

The chlorine absorber is enclosed by a jacket through which a hot or cold fluid can be pumped to maintain the absorber contents at any desired temperature. A pressure relief pipe emerging from a point near the top of the absorber is equipped with a rupture disk, a thin metal membrane designed to break if the absorber pressure rises above a certain value. If this happens, gas flows from the absorber through the relief pipe to a surge tank, lowering the pressure in the absorber while containing the released gas. 

A rupture disk device consists of a rupture disk and a clamp that holds the disk in position. The disk is made from a thin sheet of metal and is designed to burst if a set pressure is exceeded. Some rupture disks are scored so that they can burst without forming fragments that might damage downstream equipment. 

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