管道死角盲管規(guī)則

1、6d、3d、2d、1.5d管道死角/盲管規(guī)則，以及零死角閥門介紹6d、3d、2d、1.5d管道死角/盲管規(guī)則以及零死角閥門介紹關于管道死角/盲管的定義和要求，不同法規(guī)和指南有不同的要求，這些要求如下：1、1976 cfr 212規(guī)范為6d，指主管道中心到支管閥門中心的距離應小于支管直徑的6倍。2、1993 美國高純水檢查指南為6d，指主管道中心到支管閥門密封點的長度應小于支管直徑的6倍。3、2001 ispe水和蒸汽基準指南為3d，指主管外壁到支管閥門密封點的長度應小于支管直徑的3倍。4、2009 asme bpe為2d，指主管內(nèi)壁到閥門密封點的長度應小于支管直徑的2倍。5、who 建議為1.

2、5d，應避免大于分支管徑1.5倍的盲管。6、2010版中國gmp指南：為了避免將來造成混亂,本指南建議死角長度從管的外壁來考慮。我們建議避免對于最大可允許的死角做硬性規(guī)定。最后,在不考慮死角長度的情況下,水質(zhì)必須滿足要求。工程設計規(guī)范要求死角長度最小,有很多好的儀表和閥門的設計是盡量減少死角的。我們應該認識到如果不經(jīng)常沖洗或消毒,任何系統(tǒng)都能會存在死角。各種規(guī)定和提法甚至測量的方法不盡相同， 但是目前的所有提法都不是“法規(guī)”而是工程的建議和標準。thetruth about the 3d/6d rule3d/6d規(guī)則的真相the installation of pipework leads t

3、o recurrent discussions about how deadlegs can be prevented and about the maximum length outgoing pipes/pipe tees mayhave for the sensor. there is less throughflow in dead legs. hence, it isharder to clean them and during thermal sanitisation it takes longer until these"branches" have also

4、 reached the required temperature. in calls fortender and tests the 3d/6d rule is often used for the specification, but notalways in the completely correct way. in order to further explain this, pleaseread following the history of this rule.管道的安裝一再引起關于如何防止死管的討論，以及探頭安裝位置連出的支管最大長度問題的討論。在死管中水流較少，因此很難對其

5、進行清潔，并且在高溫消毒中會需要很長時間使得這些“支管”也能達到所需的溫度。在設計和測試中，3d/6d規(guī)則通常用作標準，但并不總是用的完全正確。為了進一步解釋這個問題，請閱讀以下關于此規(guī)則的歷史。the rule for the prevention of dead legs (in a wfi system) is mentionedfor the first time in the draft of the fda guides for large volumeparenterals (lvp), 21 cfr 212.49 in 1972. this requirement was ta

6、ken up inthe fda guide to inspections of high purity water systems in 1993 - onlynow it was called 6d rule. this document is still used by fda inspectors asguidance for gmp inspections. in 2001 the dead leg rule reappeared in an ispeguide. the ispe baseline guide water and steam now talks

7、about the 3drule. further statements can be found in who trs 929 (1,5 d), who trs 970 (3d)and in asme bpe-2009 (2d). this is a standard of the american society ofmechanical engineers for bioprocessing equipment. this means:防止盲管的規(guī)則（在注射用水系統(tǒng)中）首次是1972年在美國fda大容量注射劑（lvp）指南草案，21 cfr 212.49中提到的。這個要求在1993年被放

8、進了fda高純水系統(tǒng)檢查指南中-現(xiàn)在我們叫它為6d規(guī)則。該文件到現(xiàn)在還被fda檢查員用作 gmp檢查指南。在2001年，盲管規(guī)則在ispe指南中出現(xiàn)。ispe基準指南“水和蒸汽”現(xiàn)在講的是3d規(guī)則。在who trs929（1.5d）中、who trs970(3d)和asme bpe-2009(2d)有進一步的說明。這是美國生物工藝設備機械工程協(xié)會的標準。它表示： there is a 1.5d, a 2d, a 3d as well as a 6d rule.有1.5d，2d，3d以及6d規(guī)則the rule has been described for hot storage water s

9、ystems but it is also used for all cleaning in place systems (cip).規(guī)則描述的是熱水存貯系統(tǒng)，但也適用于所有在線清潔系統(tǒng)（cip）a rule of thumb became the industry standard.這種經(jīng)驗性的法則已成為行業(yè)標準。but how does it work in practice? is one rule more binding or better thanthe others?但在實踐中要怎么應用呢？是否有一個規(guī)則比其它的更具有法規(guī)效力呢？one has to know that the

10、3d and the 6d rule cannot be compared directlybecause they have a different reference point. in the case of the 3d rule thelength l of the dead leg is measured from the pipe wall of the main pipe andput in relation to the diameter of the parting pipe. the initial 6d rulemeasures the length l beginni

11、ng in the centre of the main pipe.我們必須知道3d和6d規(guī)則并不能直接進行比較，因為它們有不同的測量點。采用3d規(guī)則時，死管的長度是從主管的管壁開始測量的，與支管的直徑進行比較；而6d規(guī)則是從主管的中心線開始測量的。as a rule the "3d or shorter" has proven itself for watersystems and is said to be state of the art. but the following is also valid:the higher the risk or the value

12、 of the product the shorter. today 1.5 d isstate of the art in the case of biotechnology applications. but this may also mean that a piece of pipe in an older clean steam system may remain 6d withoutposing a gmp risk.作為一個規(guī)則，“3d或更短”已經(jīng)證明了自己對水系統(tǒng)是有用的，并被認為是理想的設計。但以下理論也是有效的：風險越高或產(chǎn)品附加值越高，設計死管更短。今天，1.5d在生物制品應用中已是理想的設計。但這也表示一個舊的潔凈蒸汽系統(tǒng)的一支管道仍可以維持其6d長度，而并沒有gmp風險。零死角閥門現(xiàn)在，零死角閥門（0d 閥門）已有生產(chǎn)，當然成本會更高一些。各個廠商所設計的零死角閥門可能會有點不一樣。下圖是一種類型的零死角閥門，紅色線為主管流向，粉色線為支管流向，閥門密封點直接在主管管壁上(即l=0d)。這種閥門的內(nèi)部結(jié)構(gòu)如下