STONEQUENCH™-LHD® Fire-Suffocating Grating Covers

Description

The STONEQUENCH-LHD® system is recommended for outdoor use and/or areas with high organic contamination:

• For recovery pits equipped with fire dampers that communicate either with a fire damper siphon or a directly connected remote pit.
• For integral retention pits, where at least 100% of the potentially burning oil volume will be contained in the retention pit.

The STONEQUENCH-LHD® cover is made of custom prefabricated LHD® fire-suffocating grating frames. The various elements are welded into panels, which are then installed on the upper part of the pit on angles designed for this purpose, forming a 3-in-1 perforated structure surface: fire-suffocating, non-slip, and handling area.

The STONEQUENCH-LHD® fire-suffocating grating cover owes its fire-suffocating effect to the perforated structure of its surface, which allows only a reduced oxygen supply to the fire. The STONEQUENCH LHD gratings, formerly patented technology, are specifically designed to accelerate the passage of burning hydrocarbons into the pit, under the gratings, more rapidly, consistently, and effectively over time than the “old” single, double-slope, or multi-slope damper models.

Once the hot oils are “trapped” in the pit, the fire self-extinguishes almost instantly due to the lack of oxygen replenishment. The suffocation phenomenon is very rapid, the temperature rise inside the pit is low, and the thermal runaway that could lead to the acceleration of fire propagation is rendered almost impossible. The device thus acts passively on 2 of the 3 components of the fire triangle in a simple and effective manner: temperature and the oxidizer (oxygen).

Description of the standard STONEQUENCH-LHD® range:

• Products tested multiple times in various independent laboratories (such as MFPA Leipzig or SP Technical Research Institute of Sweden or similar), with test report certificates in the name and ownership of the manufacturer, belonging to the manufacturer and filmed by the laboratories.
• Technical characteristics: load of 500 daN/m² distributed according to EN-14122 of 1.5 kN on 200×200 mm.
• Hot-dip galvanized steel with a minimum recommended thickness of 3 mm to ensure a deflection of less than 4 mm according to EN-14122.
• Possibility of additional surface treatment with GALVAGRID® zinc coating for anti-corrosion equivalent to or greater than C5H or C5X.
• Maximum authorized air passage of approximately 4.1% to ensure sufficient airtightness to prevent oxygen replenishment under the pit.
• Perforation hole diameter of 7mm, approx. 1065 holes per m², with about 4.1% of the surface being open.
• Minimum flow rate of approx. 660 L/min for mineral oil at a temperature of 90°C through 1 m² of cover.
• STONEQUENCH LHD non-slip gratings made of hot-dip galvanized steel, with hot-dip galvanizing certification according to ISO EN1461-2022 standard.
• Standard load-bearing capacity recommended by our engineering is 500 daN/m² (distributed load) equivalent to 2 operators and 1 oil drum of 200 L, but we can adjust it up or down according to the client’s needs and budget.

The complete STONEQUENCH-LHD® system is custom-made for easy installation. Upon request, our SPI teams or our local agent can visit the site to take measurements. Based on your plans or manual measurements, our engineering team designs and draws the system as well as the supporting structures, allowing us to offer one of the highest m² resistance on the market. Please consult us for more information.

This range also includes several accessories depending on your needs:

• SPI filtration system, when the pit is outdoors, to allow continuous drainage of rainwater; installed under the fire-suffocating cover using a concrete inspection chamber annexed to the pit.
• Non-slip access hatch to access filters, SPI pre-filtration cages, or simply the bottom of the pit.
• Upon request, we also work with stainless steel or GALVAGRID® for saline fog resistance equivalent to or higher than C5H or CXS.
• MALT modules, for grounding with braids and lugs; please specify the section to be quoted.

Depending on the configuration of your project, we offer other references of fire-suffocating covers with single-slope shutters STONEQUENCH-CCF, recommended for all types of retention pits, preferably indoors.