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标题: 60950 clause 4.3.12 可燃液体测试问题 [打印本页]
作者: someone    时间: 2007-7-13 18:12
标题: 60950 clause 4.3.12 可燃液体测试问题
60950－1中的4.3.12条要求对可燃气化物浓度进行取样检测，要求在设备周边环境中，浓度不大于其爆炸限值的50％，在点燃源附件不大于爆炸限值的25％。
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现有一喷码机，使用丁酮墨水，需要按此条检测，疑问是，标准中只说在正常使用下，那么检测应该在多大房间内进行？是通风还是密闭？因为喷码机销售后在实际使用中按照使用者的环境运行，多大房间，通风情况均不确定，有其他相关标准有规定吗？5 C' ]; C4 ?1 H; |9 ~5 j
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附上标准章节：
3 q% [! @; l; E' N6 p2 E9 _# R4.3.12 Flammable liquids7 ^1 L  H( [* S" k" `# b! S+ U7 y

0 d" p% h! q2 }9 o2 `# i+ r; q! Y& aIf a flammable liquid is used in equipment, the liquid shall be kept in a closed reservoir,
+ Z- |. O9 o) \; uexcept for the amount needed for the functioning of the equipment. The maximum quantity of
, q6 v( g3 S1 g# H: Nflammable liquid stored in an equipment shall in general be not more than 5 l. If, however, the
' E4 a$ ~3 U* b  r; k$ x! H- ausage of liquid is such that more than 5 l is consumed in 8 h, it is permitted to increase the- u& o% \% ~8 V
quantity stored to that required for an 8 h operation.
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Oil or equivalent liquids used for lubrication or in a hydraulic system shall have a flash point3 R+ F, j0 k. g
of 149 °C or higher, and the reservoir shall be of sealed construction. The system shall have
7 y4 U/ Y: V& {- j' k5 o* W6 b; rprovision for expansion of the liquid and shall incorporate means for pressure relief. This# D7 w3 @7 e% I1 T
requirement is not applicable to lubricating oils that are applied to points of friction in
8 O3 C# r. d% d. v7 |* a& a5 u& Z) Iquantities that would contribute negligible fuel to a fire.! x* [8 {8 N2 i9 S7 d3 \

, Q$ C1 u* t" G5 n' MExcept under conditions given below, replenishable liquids such as printing inks shall have a
% x& _* d  f) S* f6 M* S. cflash point of 60 °C or higher, and shall not be under sufficient pressure to cause atomization.
7 P; a, }4 M, N. {% }- cReplenishable flammable liquids that have a flash point of less than 60 °C or that are under; p0 j8 H' J. j- ]9 k0 C
sufficient pressure to cause atomization are permitted provided inspection shows that there is
' B' ~3 j& r# O9 K$ j7 s0 vno likelihood of liquid sprays or build-up of flammable vapour-air mixtures that could cause/ m) W! G9 H5 R) E. H6 E
explosion or create a fire hazard. Under normal operating conditions, equipment using a
; w( \1 G5 u  x3 d! ~flammable liquid shall not generate a mixture with a concentration exceeding one quarter of# J: \. s3 F: z: Z2 X5 _
the EXPLOSION LIMIT if the mixture is in proximity to an ignition source, or exceeding half the
" K: p5 C% e( a% T6 ^EXPLOSION LIMIT if the mixture is not in proximity to an ignition source. The investigation shall: [: f+ R; N: e7 l
also take into account the integrity of the liquid handling system. The liquid handling system
) v7 |* V) a- n( _5 qshall be suitably housed or constructed so that risk of fire or explosion is reduced, even under
* M4 @. j/ n/ o, x+ [. Mthe test conditions specified in 4.2.5.
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Compliance is checked by inspection and, where necessary, by the following test.; j4 R3 e  I- _& s
The equipment is operated in accordance with 4.5.2 until its temperature stabilizes. In this
' u, @; S& h  g) [; p+ mcondition, the equipment is operated in a normal manner, as directed in the operating) O4 G; k- s( Y6 v$ Z/ I
instructions, and samples of the atmosphere in the vicinity of the electrical components and
% ^. K: Q! N% d9 ?8 oaround the equipment are taken to determine the concentration of flammable vapours present.
8 }4 r2 w3 R, d" y; X0 @+ p: y1 G4 v3 YSamples of the atmosphere are taken at 4 min intervals; four samples to be taken during
' p5 T' E6 {& X5 N0 C8 A; Snormal operation, then seven samples after the equipment has stopped.
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If, after the equipment has stopped, the concentration of flammable vapours appears to be9 q% U" ^$ t# r9 l8 T- S
increasing, samples shall continue to be taken at 4 min intervals until the concentration is/ `+ a# l3 `7 @
shown to be decreasing.
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, \* \, o; }7 P% Z+ J2 h- R1 tIf an abnormal operation of the equipment is possible with any of its fans not running, this
, @4 m  y9 o& b* [condition is simulated during this compliance test.
作者: kinglxj    时间: 2007-7-13 22:06
这个在标准是没有明确规定，所以只是我们只是需要理解“正常使用下”，按照正常理解是你所列举的情况都可以的，但是做内部设计认证最好按照最严酷等级来进行，做实验室认证，一般有专门实验室，没有特殊要求，看是否按照常规情况进行！2 t' k8 n" V8 A/ _; N
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这个只是理解，仅仅参考，没有其他意思！
作者: barry    时间: 2007-7-14 10:21
引用第0楼someone于2007-07-13 18:12发表的 60950 clause 4.3.12 可燃液体测试问题 :  l- p* _1 t. y* k8 A3 A
60950－1中的4.3.12条要求对可燃气化物浓度进行取样检测，要求在设备周边环境中，浓度不大于其爆炸限值的50％，在点燃源附件不大于爆炸限值的25％。
, a; V1 W# g5 O' @8 t. V, L
6 V4 Q2 Y& O6 |8 S5 r) q2 M现有一喷码机，使用丁酮墨水，需要按此条检测，疑问是，标准中只说在正常使用下，那么检测应该在多大房间内进行？是通风还是密闭？因为喷码机销售后在实际使用中按照使用者的环境运行，多大房间，通风情况均不确定，有其他相关标准有规定吗？
+ F) R/ z) j7 Q* Y% ^7 g# o- z7 a7 d; i/ ~" i* S
附上标准章节：* @. r* Y& H, x  L+ ~
.......

% Z2 ^, q# y# N5 t这个问题好偏，做了这么多年的60950，第一次见到这个问题。。。- c' ~: j7 k, [. ~+ `

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