Interpretation Response #18-0115
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Chemring Energetic Devices
Individual Name: Austin Ruf
Location State: IL Country: US
View the Interpretation Document
Response text:
March 18, 2019
Austin Ruf
Mechanical Engineer
Chemring Energetic Devices
2525 Curtiss Street
Downers Grove, IL 60515
Reference No. 18-0115
Dear Mr. Ruf:
This letter is in response to your August 6, 2018, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the packing instructions included in the explosive competent authority approval (EX approval) EX2012050060.
We have paraphrased and answered your questions as follows:
Q1. You ask whether the HMR define the word “shunt” as used in EX approval EX2012050060.
A1. The answer is no. The HMR does not define the word “shunt.”
Q2. You ask whether the word “shunt” implies a physical pin-to-pin connection, i.e. a shorting spring or clip.
A2. The answer is yes. Although the HMR do not define “shunt,” it is the opinion of this Office that the packing instruction in EX2012050060 requires the use of a physical connection that ensures that all parts of the device that are connected to the bridgewire are maintained at the same electrical potential to prevent the flow of any extraneous current.
Q3. You ask whether the use of a Faraday cap or RF cap is sufficient to be in compliance with EX2012050060.
A3. The answer is no. Faraday or RF caps do not provide protection against the build-up of a difference in electrical potential between the leg wires. Additionally, any offeror who wishes to modify the design of an approved explosive device must seek a modification of the EX approval. Each modification request will be considered on a case-by-case basis.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division