Bolt and Nut Inspection and Test Plan

This content provides you with a template for Bolt and Nut Inspection and Test Plan. This bolt and nut ITP is a general ITP and need to be completed and modified based on your purchase order specification. You need to review your bolt and nut vendor proforma invoice and your purchase order and change this inspection and test plan.

The I4I Academy API 570 Piping Inspector Course in the ASME B31.3 section covers inspection and testing requirements for bolts and nuts. The same was also covered in the API SIFE Course.

Bolt and Nut Inspection and Test Plan TaskVendorTPI InspectionClient
Mill test reports (including heat treatment record, etc.) or Certification of ConformityHHR
Metallographic examination, if applicableHWR
Visual and dimensional control (Sampling test is required as per manufacturer's standard)HWR
Stamping, marking and color coding check (Sampling test is required as per manufacturer's standard)HSR
Final visual inspection including packaging and quantity controlHHR
Documentation review prior to release(Final activity of Technical Inspection)HHR
Pre-shipment InspectionHHR

Bolt and Nut Inspection and Test Plan - Points

H: Hold Point implies that relevant production activities shall not proceed until the continuation of work is permitted by Purchaser. (Notification req'd)

W: Witness point implies that Purchaser intends to witness the designated inspection feature. If Purchaser decides not to witness the relevant feature, production can proceed without permission of Purchaser. (Notification req'd)

S: Witness, but spot check basis. Initial operation will be witness point and subsequent operation will be witnessed at discretion of Purchaser considering the results of previous inspection. (Random Inspection : Notification not req'd)

R: Review inspection & test records (Notification not req'd)

The hold, witness and review points selection in above ITP, depend to the bolt and nut buyer, but as general when the bolts and nuts will be applied in high temperature services or in low temperature services, then the higher inspection grade will be considered. 

Both of these services are very critical, so it is necessary precise inspection to be done in manufacturing process. The bolts and nuts in these services are low alloy steels or even high alloy steels. Some purchasers assign resident inspectors in the vendor shops to supervise construction processes and witnesses all tests.

When the bolts and nuts services is a general ambient condition, then normally only a pre-shipment inspection is conducted by TPI inspection.

The pre-shipment inspection agency will checks quantity, document review, visual quality, packing and marking.