What I've known is that generally, hanger support consists of rod, clevis, clamp, fastener and etc. When it comes to hanger supports, I would like to request you to share your knowledge about it. Based on NFPA 13(2010 E) sec. 18.104.22.168.2, it is stated as below,
<NFPA 13 2010 E>
22.214.171.124.1 Unless permitted by 126.96.36.199.2 or 188.8.131.52.3, the components of hanger assemblies that directly attach to the pipe or to the building structure shall be listed.
184.108.40.206.2* Mild steel hangers formed from rods shall be permitted to be not listed.
A.220.127.116.11.2 Generic items utilized with hanger rods and fasteners are not required to be listed. These include such items as bolts, screws, washers, nuts and lock nuts.
<NFPA 13 Handbook>
Mild steel rod hangers are not required to be listed according to 18.104.22.168.2, since standard practice has demonstrated that rods in the sizes required in Table 22.214.171.124 can support, at maximum permitted spacing, five times the weight of water-filled Schedule
40 pipe plus 250 lb (114 kg) applied as a temporary point load. U-bolts, U-hooks, and eye rods are also considered types of mild steel hangers formed from rods and meet the conditions of 126.96.36.199.2.
Although 188.8.131.52.3 states that screws, bolts, and other fastener items identified in 9.1.3, 9.1.4, and 9.1.5 are considered part of the hanger assembly and do not require listing, this exemption does not override the provisions of those subsections that require specific items to be listed. Other fasteners not specifically identified in 9.1.3, 9.1.4, or 9.1.5 must be listed.
When selecting the proper material for a trapeze hanger, it is not the intent to require that the pipe or angle iron used as a trapeze component be listed, only that the pipe or angle iron meet or exceed the required section modulus. However, all other components that attach to the trapeze member are required to be listed.
According to the specification above, it seems that the rod of mild hanger support is not required to be listed along with generic items including bolts, screws and so on. But there is no mention about the components which would be directly attached
to the pipe or to the building structure of sec. 9.1.14, for example clevis and clamp. I think that those components (such as clevis and clamp) might be required to be listed in line with the requirement sec. 184.108.40.206, although those are made of mild still. That’s because the requirement of listing for those is not indicated specifically like generic items of A 220.127.116.11.2. Would you confirm if my understanding is correct? If possible, please specifically let me know which component shall be listed.
Thank you very
much in advance for your prompt response.