Dairyland
Gradient Control Mats (GCM)
SKU: GCM
Engineered Ground Mat Performance
Personnel working near pipelines can be subject to electrical hazards such as lightning, AC fault current/voltage, and steady-state AC induction. Dairyland offers engineered Gradient Control Mats (GCM) to address lightning and AC fault current conditions effectively. Safety risks from step and touch potentials are now limited with our grid-type mat, in a much lower cost design. Dairyland also recommends decoupling gradient control mats to improve CP on the pipeline using the SSD.
Key Benefits
- Safe Touch and Step Potentials: Designed to limit step and touch potentials due to lightning, keeping them well below the levels required by IEEE 80 for power frequency voltages.
- Long Design Life: Galvanized steel gradient control mat is designed for long life in all soil conditions when cathodically protected using readily available magnesium anodes. The anode design life is 20 years.
- Flexible Sizing: Available in 4' × 8' sheets that can be joined together to form any larger size mat required.
- Decoupling Advantages: When connected through a Dairyland Solid-State Decoupler (SSD), the mat prevents stray DC currents from accessing the pipeline, allows CP readings near the mat, and eliminates interaction between the CP system and gradient control mat.
- Lower Installed Cost: Total installed cost will normally be less than a pure zinc mat of any construction, particularly when an 8' × 8' or larger mat is required.
Specifications
- Mat Dimensions: 4' × 8' sheets.
- Wire Material: 0.135" diameter steel wire.
- Wire Spacing: 3" × 3".
- Wire Intersections: All wire intersections welded.
- Coating: Hot-dip galvanized after welding.
- Weight: 15 lb (6.8 kg) per mat.
- Shipping: Shipped flat on pallets.
- Larger Mat Configurations: Individual sheets can be joined together to form any size mat required. Provision is made for thermit welding adjacent mat sections together to form an electrically continuous mat and for thermit welding lead connections to the mat.
- Recommended Anodes: Packaged magnesium anodes, either high-potential (Alloy M1C) or H1-Alloy (Standard), selected according to mat size and soil resistivity.
- Anode Design Life: 20 years when decoupled from the pipeline.
- Recommended Decoupler: Dairyland SSD-2/2-1.2-100 for most applications; blocks ±2.0 V, with a 1.2 kA fault current rating at 30 cycles and a 100 kA lightning current rating (8 × 20 μs).
- Installation Clearance: Trim mat wire to be no closer than 3" from the pipe wall.
- Recommended Conductor Length: Keep the conductor connecting the mat to the pipeline as short as possible, preferably 8" (200 mm) or less.
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Shipping & Returns
Shipping costs and delivery timelines vary by order. All returns require prior written approval and may be subject to a restocking fee.
Please review our Terms & Conditions for complete shipping, return, and warranty details.
