按ASME标准设计时, 高颈法兰与筒体对接采用对接焊接接头(Butt weld),属于C类焊缝,现在设备整体要求是Spot RT,筒体直径是1000mm,厚度为10mm,在这种情况下,高颈法兰与筒体对接的C类焊缝,是否也需要Spot RT? 为什么?

[ 本帖最后由 xrg0519 于 2008-9-25 22:02 编辑 ]

主要看图纸上的设计要求吧。

一般C类焊缝不用100%拍片的。不放心的话可以做下PT

楼主的描述不清楚啊，高颈法兰直接和筒体连接？

IF THE JOINT BETWEEN LONG NECK TO MAIN SHELL IS BUTT WELDED.
FROM MY CONCERN, IT COULD BE TREATED AS B-CATEGORY PER UW-9 AND FIG UW-3.
AS FOR THE THICKNESS OF SHELL IS LESS THAN 10MM, I THINK RT COULD BE EXEMPTED PER UCS-56.

引用:

原帖由 zlc096 于 2008-9-25 10:21 发表
主要看图纸上的设计要求吧。

一般C类焊缝不用100%拍片的。不放心的话可以做下PT

该设备中,高颈法兰与筒体对接的C类焊缝,肯定是不需要 Full RT的,问题是现在需不需要Spot RT,我不确定!

引用:

原帖由 kimishen 于 2008-9-25 14:42 发表
楼主的描述不清楚啊，高颈法兰直接和筒体连接？

高颈法兰与筒体对接的对接接头焊缝

引用:

原帖由 tony_symingtong 于 2008-9-25 20:43 发表
IF THE JOINT BETWEEN LONG NECK TO MAIN SHELL IS BUTT WELDED.
FROM MY CONCERN, IT COULD BE TREATED AS B-CATEGORY PER UW-9 AND FIG UW-3.
AS FOR THE THICKNESS OF SHELL IS LESS THAN 10MM, I THINK RT COU ...

    在ASME标准中,属于C类焊缝,GB150中属于B类焊缝!

my asme code is english version, currently no chinese version in hand.
see the definition of category  B: circumferential welded joints with the main shell, communicating chambers nozzles or transitions in diameter.
noted that the portion of long neck flange to main shell is NECK to shell butt weld.
the nozzle to flange is integral type and can be assumed as seamless joint.
the key point is what geometry shape of parts to shell, here it could treat as nozzle pipe to shell pipe at easy.

See the definiton of category C, welded joints connecting flanges, van stone laps tubesheets or flat heat to main shell... or any welded joint connecting one side  plate to another side plate of flat side vessel. Here the joint is lap/fillet weld other than BUTT weld. The category joint from my opnion is Shell (pipe) to plate or plate to plate.

as for GB, i have no point about it as for I never touch it.

AB类焊缝也只是SPOT RT的话，C类一般就不用做SPOT RT了。

个人意见，仅供参考。

高颈法兰与筒体对接的C类焊缝,需要Spot RT,因为ASME规定的是对接接头进行RT,它实际上相当于GB150中的B类焊缝。