There are mainly two kinds of pipe flange standards for important pipe connection at home and abroad, namely European system (by din

標準表示）和美國系統(tǒng)（由美國ASMEB 16.5，B16.47表示）。 標準具有代表性）。 同一系統(tǒng)中/地區(qū)的管道法蘭標準基本上相互兼容（連接尺寸和密封表面尺寸）。 不能將兩個不同的系統(tǒng)一起使用。

Standard) and US system (represented by asmeb 16.5, b16.47). The standard is representative). The pipe flange standards of the same system are basically compatible with each other (connection size and sealing surface dimension). You cannot use two different systems together.

（1）GB50316的相關規(guī)定

(1) Relevant provisions of GB 50316

1。 緊固件用于管道：包括六角頭螺栓，雙頭螺栓，六角頭螺母和墊圈等。

1。  Nuts, hexagon bolts, etc. for fastening pipes.

2。 從當前標準中選擇標準緊固件，然后選擇指定特殊用途的材料

2。  Select standard fasteners from current national standards, and then select materials for specific applications

3。 用于法蘭連接的緊固件材料應符合現(xiàn)行的法蘭標準要求，并與法蘭墊片兼容。

3。  The fastener materials used for flange connection shall meet the requirements of current national flange standards and be compatible with flange gasket.

4。 用于法蘭連接的緊固件螺紋的螺距不應大于3mm，并且直徑為M30或更大的緊固件可以是細螺紋。

4。  The screw pitch of fasteners used for flange connection shall not be greater than 3 mm, and fasteners with diameter of M30 or larger can be fine threads.

5。 碳鋼緊固件應符合當前標準

5。  Carbon steel fasteners shall meet current national standards

6中規(guī)定的工作溫度。 在嚴重的循環(huán)應力條件下螺栓或雙頭螺栓，樣品由合金鋼制成。

6. Under severe cyclic stress conditions, the sample is made of alloy steel.

（2）“設備通用原則”的有關規(guī)定

(2) Relevant provisions of "general principles of equipment"

1。 法蘭緊固件應確保墊片滿足初始密封條件，并在整個操作過程中保持墊片密封。

1。  Flange fasteners shall ensure that the gasket meets the initial sealing conditions and maintains gasket sealing throughout the operation.

2。 在高溫條件下，應使用PN≤2.0MPa的六角形頭螺栓或全螺紋螺栓或等長雙頭螺栓。

2。  Under high temperature condition, hexagon head bolt or full thread bolt or equal length stud bolt with PN ≤ 2.0MPa shall be used.

3。 屈服強度不超過235MPa，低強度緊固件僅適用于PN≤2.0MPa非金屬墊片的法蘭連接，不應在嚴酷的循環(huán)場合使用，碳鋼低強度緊固件]的工作溫度范圍 是-20℃?200℃。

3。  The yield strength shall not exceed 235mpa. Low strength fasteners are only suitable for flange connection with PN ≤ 2.0MPa non-metallic gasket, and shall not be used in severe cycling situations. The working temperature range of carbon steel low-strength fasteners is - 20 ℃? 200 ℃.

4。 當非軟墊圈法蘭連接使用變形和硬化的奧氏體不銹鋼緊固件時，應檢查緊固件的承載力，是否滿足連接要求，并且使用溫度不超過500℃。

4。  When deformed and hardened austenitic stainless steel fasteners are used in non gasket flange connection, the bearing capacity of the fasteners shall be checked to see if they meet the connection requirements, and the service temperature shall not exceed 500 ℃.

5。 它應滿足緊固件對管道法蘭（SH3404）的要求或相關標準。

5。  It shall meet the requirements of fasteners for pipe flange (sh3404) or relevant standards.

（3）選擇用于法蘭連接的螺栓和螺母

(3) Select bolts and nuts for flange connection

螺栓根據(jù)其形狀螺栓分為單頭而雙頭螺栓，單頭螺栓僅在螺釘?shù)囊欢思庸ぢ菁y，另一端是連接到螺釘本體的螺釘頭。 法蘭的單頭螺栓通常使用六角頭螺栓。 兩端螺栓的兩端均加工有螺紋，并呈圓柱形。 當擰緊力較大時，單頭螺栓容易在螺釘和螺釘頭之間的連接處斷裂，因此不能在中壓和高壓法蘭上使用。 雙頭螺栓不僅可用于中壓和高壓法蘭，而且還易于從兩側擰緊。

According to its shape, the bolt is divided into single head bolt and stud bolt. The single head bolt only processes thread at one end of the screw, and the other end is the screw head connected to the screw body. Hexagon head bolts are usually used for single head bolts of flanges. Both ends of the bolts at both ends are machined with threads and are cylindrical. When the tightening force is large, the single head bolt is easy to break at the joint between the screw and the screw head, so it can not be used on medium pressure and high pressure flange. The stud bolts can not only be used for medium and high pressure flanges, but also can be easily tightened from both sides.

法蘭螺母通常為六邊形，分為單倒角和雙倒角兩種類型。 單個倒角六角形螺母與連接的零件接觸的表面是平坦的，僅在另一側倒角； 雙斜切六邊形螺母的兩邊都斜切了。 因此，與連接器的接觸面積是單倒角六邊形螺母的接觸面較大，而雙倒角六邊形螺母的接觸面較小。

Flange nuts are usually hexagonal and can be divided into single chamfering and double chamfering. The contact surface of a single chamfered hexagon nut with the connected parts is flat and chamfered on the other side only; both sides of the double bevel hexagon nut are chamfered. Therefore, the contact area with the connector is that the contact surface of single chamfered hexagon nut is larger than that of double chamfered hexagon nut.

螺栓根據(jù)制造方法分為粗制螺栓，半精制螺栓和精制螺栓。 除螺紋部分外的粗糙的螺栓，其余部分的外表面未精加工，是坯料的粗糙形狀，相對較粗糙。 螺栓主要由普通碳鋼制成，其張力不高。 半精制和精制螺栓需要進行處理，有些需要進行熱處理。 它們主要用于制造碳素鋼或合金鋼，因此它們的張力大且耐熱性高。

According to the manufacturing method, bolts are divided into rough bolts, semi refined bolts and refined bolts. The rough bolt except for the threaded part, the outer surface of the rest part is not finished, which is the rough shape of the blank, relatively rough. The bolt is mainly made of ordinary carbon steel and its tension is not high. Semi refined and refined bolts need to be treated, some need heat treatment. They are mainly used to make high quality carbon or alloy steel, so they have high tension and high heat resistance.