PRIMADET® non-electric delay detonators Noiseless trunkline delays
PRIMADET® non-electric delay detonators Noiseless trunkline delays (NTD) function The Primadet® Noiseless Trunkline Delay (NTD) non-electric delay detonator products are used as surface delays with detonating cord, and/or shock tube downlines. The system is commonly used in ‘air blast’ sensitive areas as it is considered ‘noiseless’. description Noiseless Trunkline Delays (NTD) are Primadet® non-electric delay detonators whose lengths and delay times are suited for use as trunklines in surface blasting. NTDs are factory-assembled units with the following main components: • Shock tube to transmit a signal to the delay cap. The shock tube is a 3mm diameter plastic laminated tube coated inside with a thin layer of HMX / Aluminium dust, which reliably transmits a low energy signal at approximately 2000m/s from one point to another. Due to the shock tube construction and inner Surlyn tube, the low energy signal will propagate through most sharp bends, knots and kinks that may occur in the shock tube. The outer surface of the tube remains intact during and after functioning. The distinguishable tough, orange outer jacket gives excellent abrasive, oil resistant and tensile properties. • The Noiseless Trunkline Delays (NTD) have a precise surface delay. The delay contains integral delay elements, anti-static protections and patented safety devices. Standard delay times can vary according to requirements and combinations. • A bunch block is used to attach the blasting cap to the detonating cord or shock tube downline (s). The block contains the detonator and is colour coded according to delay times. • A colour-coded “J” hook is an inert fitting at the initiation end of the Noiseless Trunkline Delays (NTD), for quick and reliable connection to Primacord detonating cord downlines or “pigtails”. • Tape used to bind each unit in a coil, facilitating easy deployment and a reduced chance of tangling. • A delay tag to indicate the nominal delay time of the detonators.