STEMPAC™ — Tech Info
Document type: Tech Info
Categories: Blasting Accessories

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Technical
Stempac Information

Properties

Description StemTite Blast Control Plug
Stempac is an underground stemming device used to retain explosive energy in
blastholes drilled underground. The Stempac consists of a StemTite® Blast Multi Start Tapered Thread
Control Plug surrounded by selected aggregate that is contained within a sleeve. No part of the device is explosive in nature. The Stempac is held in the hole by a StemTite Blast Control Plug
retention spider. In operation the explosive energy released on detonation from the
associated charge wedges the StemTite Blast Control plug into the surrounding Sock
aggregate. This redirects the energy of the blast into the blasthole wall, which
effectively contains the explosive energy. 8 – 10mm Aggregate
The Stempac stemming system consists of three components:
 Stainless Steel Shaft (Insertion Tool)
1. The Stempac Device
The Stempac device is an assembly of StemTite plugs and selected crushed StemTite Blast Control Plug
aggregate. These components are contained in a package manufactured from a
deformable material. The deformable material permits the Stempac to increase its PVC Sleeve
diameter to fit variations in the designated blasthole diameter. 2. The Installation Tool Redcap
The installation tool consists of a stainless steel rod, which has a tapered multi
start thread on the end. The stainless steel rod is fitted to a length of PVC conduit. 3.

he Installation Tool Redcap
The installation tool consists of a stainless steel rod, which has a tapered multi
start thread on the end. The stainless steel rod is fitted to a length of PVC conduit. 3. The Red Cap Retention Spider
The function of the red cap is to retain the Stempac in the blasthole and allow for Installation Tool
the tamping of the stemming contained in the Stempac. The red cap has a hole
drilled through the end to allow placement on the end of the insertion tool. The red
cap is a standard device used to hold emulsion product in upholes.

Dyno Nobel Asia Pacific Pty Limited (ACN 003 269 010) is a subsidiary of
Version 7
 Incitec Pivot Limited (ACN 004 080 264) Level 8, 28 Freshwater Place, Southbank Vic 3006
January 2018
 Phone 1800 251 872 Fax 07 3026 3999 www.dynonobel.com

®

Technical
Stempac Information
Application
Attachment of Insertion Tool Installation into the blasthole (continued)
1. Place the Red Cap onto the stainless steel rod ready for placement into the 6. Tamp the stemming into place by pulling back hard on the insertion tool. This
 blasthole. (The plastic sleeve is part of the Stempac and should not be will spread the stemming at the closed end of the Stempac to the size and
 removed.) shape of the blasthole. This stemming protects the centre Stemtite plug from
 the heat of the blast, which is of vital importance. 2. Push the installation tool rod through the tube in the centre of the Stempac until
 it bottoms. 7. Turn the insertion tool to unscrew from the Stempac and withdraw the insertion
 tool from the blasthole. 3. While holding the insertion tool, turn the Stempac by the closed end until a
 definite resistance can be felt. To ensure the Stempac is attached firmly to
 the installation tool, hold the installation tool steady while pulling back on the
 Benefits
 closed end of the Stempac. The Stempac should be attached to the
 installation tool ready for installation into the blasthole. • Good stemming practices, with controlled energy retention prevents cratering
 and results in less damage to the brow of the stope. Installation into the blasthole
 • Effective stemming contains explosive gases, increasing the energy imported
1.

rgy retention prevents cratering
 and results in less damage to the brow of the stope. Installation into the blasthole
 • Effective stemming contains explosive gases, increasing the energy imported
1. While holding the installation tool, with the Stempac attached in a vertical up to the rock mass. position, pull down on the lower open end of the Stempac. (This will stretch
 the Stempac, maximising the length and minimising the diameter, to ensure the • Effective stemming results in improved fragmentation of the blasted rock. section containing the aggregate is smaller than the diameter of the blasthole. • Effective stemming greatly reduces airblast and the damage caused as a
 If the Stempac has had excessive handling it may be necessary to kneed the result of airblast. aggregate to reduce the diameter. The Stempac is now ready for placement in
 the blasthole. • Simple and easy to use and can be incorporated into charging procedures for
 underground blastholes. 2. Clip the NONEL lead(s) into the gate in the red cap. • Ready for immediate use and conveniently packaged for underground storage. 3. Place the closed end of the Stempac into the blasthole and push it until the red
 cap fingers engage the blasthole wall. 4. Pull back on the NONEL lead to ensure it is free and has not become tangled. 5.

ce the closed end of the Stempac into the blasthole and push it until the red
 cap fingers engage the blasthole wall. 4. Pull back on the NONEL lead to ensure it is free and has not become tangled. 5. While holding the NONEL lead slowly push the Stempac device into the
 desired position in the blasthole. It should be noted that the Stempac cannot
 be retracted because the red cap can only travel in one direction.

Dyno Nobel Asia Pacific Pty Limited (ACN 003 269 010) is a subsidiary of
Version 7
 Incitec Pivot Limited (ACN 004 080 264) Level 8, 28 Freshwater Place, Southbank Vic 3006
January 2018
 Phone 1800 251 872 Fax 07 3026 3999 www.dynonobel.com

®

Technical
Stempac Information

Handling Safe handling, transportation and storage
It is advisable not to handle the Stempac more than necessary prior to installation. First Aid – This product is manufactured from inert material.
 Safety – The device itself is non-explosive, however, it is designed for use with
Packaging explosives which are classified as dangerous goods and these can cause
 personal injury and damage to property if used incorrectly.
The Stempac is delivered enclosed in a plastic sleeve and packaged in cartons.
Each carton has a nominal weight of 30 kilograms. It is available in sizes to suit 76, Transportation and Storage – The carton has a nominal weight of 30 kilograms
89 and 102 millimetre diameter blastholes. and as such requires appropriate manual handling precautions. There are no
 specific storage requirements or constraints.

Hole Size Quantity per box
 76mm 14
 89mm 10
 102mm 9

Product Disclaimer The explosive products discussed in this document should only be handled by persons with the appropriate technical skills, training and licences. While Dyno Nobel has made every effort to
ensure the information in this document is correct, every user is responsible for understanding the safe and correct use of the products. If you need specific technical advice or have any questions, you should contact
your Dyno Nobel representative. This information is provided without any warranty, express or implied, regarding its correctness or accuracy and, to the maximum extent permitted by law, Dyno Nobel expressly
disclaims any and all liability arising from the use of this document or the information contained herein. It is solely the responsibility of the user to make enquiries, obtain advice and determine the safe conditions for use
of the products referred to herein and the user assumes liability for any loss, damage, expense or cost resulting from such use. ® DYNO, GROUNDBREAKING PERFORMANCE, DYNOSPLIT, RiGHT and the Blasting
Accessories and Explosion device are registered trademarks of the Dyno Nobel / Incitec Pivot Group. ® StemTite is a registered trademark of Stemtite, Inc. © Dyno Nobel Asia Pacific Pty Limited 2018 Reproduction
without permission strictly prohibited.

Dyno Nobel Asia Pacific Pty Limited (ACN 003 269 010) is a subsidiary of
Version 7
 Incitec Pivot Limited (ACN 004 080 264) Level 8, 28 Freshwater Place, Southbank Vic 3006
January 2018
 Phone 1800 251 872 Fax 07 3026 3999 www.dynonobel.com