Case study of explosion of combustion of conduit of a few kinds of common oxygen, valve
- source:LONTL CNC Machining
When 1MPa, forbidden of use brake a powerful person 0.
When P>10MPa of 6MPa , completely cupreous radical alloy. In recent years, as the addition of aerobic dosage, the large family that use oxygen uses aerobic conduit to carry. Because pipeline is long, distributing wide, plus leave urgently or fast close valve, cause aerobic conduit and the accident that valve combustion explodes to happen from time to tome, so, comprehensive analysis is aerobic conduit and the hidden trouble that an unexpected winner exists, critical, taking corresponding step is crucial. One, of case study of explosion of combustion of conduit of a few kinds of common oxygen, valve 1.
Broken bits of the ferruginous, dust inside conduit, solder and conduit wall or attrition of mouth of a powerful person produce combustion of high temperature happening. The sort of this kind of circumstance and impurity, granuality and air current speed are concerned, iron pink is easy burn with aerobic happening, and granuality is finer, burning point is lower; Gas fast faster, produce combustion more easily. 2.
Inside conduit or the material of the low burning point such as valve existence grease, balata, ignition falls in local high temperature. A few kinds of combustible are in oxygen (often press below) ignition point: Combustible name burning point (℃ ) lube 273 -- paper of 305 steel fills up 304 balata 130 -- balata of 170 fluorine 474 3 chloric second 392 get together 4 fluorine ethylene 507 3.
Heat insulation compresses the high temperature of generation to make combustible combustion is 15MPa before a powerful person for example, temperature is 20 ℃ , it is after a powerful person often press 0.
1MPa, if open valve quickly, temperature of the oxygen after a powerful person compresses formulary computation to be able to amount to 553 ℃ by heat insulation, this already was achieved or exceed certain material catch fire dot. 4.
The burning point of the combustible in high-pressured pure oxygen is reduced is conduit of oxygen of inducement of flaming of aerobic conduit valve and valve in high-pressured pure oxygen, its danger sex is very big, the experiment proves, catch fire detonate can become inverse ratio with pressure square, these tracheal to oxygen paths and valve formed huge to browbeat. 2, be on guard measure 1.
The design should accord with concerned code, standard to stipulate the design should accord with what metallurgy ministry issued 1981 " a certain number of regulations of net of valve of steely enterprise oxygen " , and " oxygen and relevant gas emergency decree " (GB16912-1997) , " aerobic station design is normative " (GB50030-91) wait for code standard requirement. (1) the largest velocity of flow of the oxygen in carbon steel canal should accord with next watches. The largest velocity of flow of the oxygen in carbon steel canal: Actuating pressure (MPa) ≤ 0.
1 -- 0.
6 -- 1.
6 -- 3.
0 velocity of flow (M/s) of of 20 13 10 8 (2) catch fire to prevent, after aerobic valve, all should join a paragraph of its length diameter of not less than 5 times canal, and not less than 1.
The copper of 5m base the conduit of alloy or stainless steel. (3) aerobic conduit should set bend and fork head less as far as possible, actuating pressure prep above 0.
The oxygen of 1MPa is in charge of path bend, should adopt strike out a powerful person flange to make. The air current direction of fork head, should arrive into 45 ° with direction of director air current 60 ° horn. (4) in concave and convex to solder flange, use red copper welding wire to make O sealing ring, it is oxygen uses the sealed form with flange reliable flame resistance. (5) the good fit with aerobic due and electric conduit, ground connection resistor should be less than 10 Ω , the resistor between flange should is less than 0.
03 Ω . (6) the extreme of main oxygen conduit inside the workshop should be added set diffuse to be in charge of, enrage conduit with benefit oxygen blow sweep and displacement, before longer aerobic conduit enters workshop control valve, should set filter. 2.
Installation note (1) every and the place that oxygen contacts want strict and defatted, defatted hind with not the dry air of oiliness or nitrogen aspiration. (2) solder reinforce uses argon arc solder or arc welding. 3.
Operation note (1) answer when switch oxygen valve slow undertake, operation personnel should stand in the flank of valve, open should reach the designated position. (2) forbidden blow with oxygen brush conduit or try leakage with oxygen, try pressure. (3) implement operation ticket system, make to operating purpose, method, condition beforehand relatively expatiation and regulation. (4) the hand that the diameter is more than 70mm moves aerobic valve, press difference to narrow to 0 when around of a powerful person.
The ability when 3MPa less than allows to operate. 4.
of note of care and maintenance (1) aerobic conduit often should be checked safeguard, brush paint except rust, every 3 -- 5 years. (2) watch of the relief valve on pipeline, pressure, want fixed desired result, 1 year 1. (3) device of perfect ground connection. (4) before get angry works, should undertake displacement, blow sweep, content of the oxygen in blowing a gas is in 18 ％ -- qualification is when 23 ％ . (5) valve, flange, spacer and tubal material, pipe fitting is chosen should accord with " oxygen and relevant gas emergency decree " (GB16912-1997) concerned regulation. (6) establish technical record, groom operation, the overhaul, maintain staff. 5.
of other safety precaution (1) raise construction, overhaul and operation personnel to be spent to safe heavy visual range. (2) the vigilance that raises administrator. (3) raise level of science and technology. (4) ceaseless and perfect plan sending oxygen. Summary: Because the sealing surface of brake a powerful person is moving relatively,causing the cause that detains a powerful person that use dam up water truly is actually (namely the switch of valve) in because chafe,be met and cause abrade to damage, once damage, have " iron pink " fall off from sealing surface place, the iron pink of so petty grain catchs fire very easily combustion, this ability is truly dangerous place. In fact, oxygen detains a powerful person that use dam up water on gas pipeline, other shut-off valve have an accident to happen euqally, the sealing surface of shut-off valve can damage euqally, produce risk euqally likely, the experience of a lot of enterprises is aerobic conduit introduce valve of cupreous radical alloy entirely, need not valve of carbolic steel, stainless steel. Valve of cupreous radical alloy has mechanical strength tall, wear-resisting caustic, security is good (do not arise electrostatic) wait for an advantage, so real reason is the sealing surface because of brake a powerful person wears away extremely easily and the scrap of generation just is a culprit, dropping as to sealing was not crucial. Explosive accident appears like a lot of oxygen conduit that did not employ brake a powerful person in fact, appear in valve commonly two side press difference bigger, the instant with valve faster open, for many times the accident also makes clear, catch fire source and combustible are ultimate reason, a kind of method that detaining a powerful person that use dam up water is control combustible nevertheless just, and keep clear of regularly the ferruginous, defatted, purpose that prohibits the instrument such as oil is same, as to control it is velocity of flow, good to do electrostatic ground connection is to eliminate catch fire source. The individual thinks valve material is the first element character, also appear on hydric conduit similar problem, new standard already will " detain a powerful person that use dam up water " word take out, it is a clear proof, the key must find a reason, a lot of enterprises handle pressure without giving thought to at all actually, uniform employ a powerful person of cupreous radical alloy forcibly, but the accident that has explosion euqally appears, so control catchs fire source and combustible, safeguard meticulously, stretch tight closely safe this bowstring just is the most crucial. CNC Milling CNC Machining