Load class b trench drains. 20. Load class b trench drains

 
20Load class b trench drains  Filter

Available 1 product. $ 585. Gray. Additional information. 34" H. These grates are built to support pedestrian foot traffic. ) Whether the system is for private or commercial use – to determine the frequency of traffic. 062" inner depth range. SKU: DS-664 UPC: 052063606644. The Wedge Wire grate is load Class B allowing for any light maintenance or service vehicles to access the area, is slip resistant rated to R11 (AS4586), heelproof (openings less than 8mm) and resistant to bicycle tyre penetration (AS3996). The trench excavation must be large enough to accommodate each of the following: Load Class a) Channel/catch basin width and depth dimensions b) Surrounding concrete dimensions* c) Compacted gravel baseHeavy Duty Grate design load of at least 56,200 lbs per foot. Recommended for medium-duty pneumatic tire traffic, autos, and light trucks at speeds less. Specification Sheet for IA-INTER-0520-HP-BF. Some catch basin grates have screws or a locking device of some sort to hold the grate down. The Swiftdrain 600 trench drain system consists of 32 pre sloped and neutral channels. 0% Y Y SS Stainless Steel Slotted 48" Class B 23. T200-PGB-13-LS Galvanized Longitudinal Bar Grate. Open surface area 19. Designed to fit the FP1200 Series channel drain by Trench Drain Systems. TRENCH DRAIN. If the grate securing bolts are left out of the grates, the life span of the trench drain system could be affected along with the safety of pedestrian traffic. slab and around the trench drain. 25″ dia. place trench drains (470 GPM per outlet attainable with proper components). Popular Manufacturers. Ductile iron, galvanized, stainless steel, and polypropylene gratings to meet DIN 19580 Load Classifications A throu. Load Rating Class: 3000 psi: B: 4000 psi: B: 5000 psi: B: Material: Color: Traffic Edge Thickness (in) Bearing Area (sq in/ft) Opening Width (in) Open Area. Dura Slope offers versatility and easy installation featuring interlocking joints that snap-together. View Product. Made to fit the Zurn® Z806, Z886, Z886-ST, Z890 and Zurn Z883 trench drain systems. Toll Free: 800. Trench Drain Z886 6″ [152 mm] external wide pre-sloped trench drainage system as a 0. 7 x 4. 25″ x 1. 1. Add to cart. A trench drain is a continuous line of surface drainage that removes liquid from a specific area. Dimension(s): 4' L x 6"W x 5. It is also important to determine the width of the drain, which is typically the width of the grate plus 1/4. Compatible with NDS Mini Channels or consider Trench Drain Systems’ MAX mini drainage system with decorative stainless steel grates. We also have three fabrication material options: stainless steel, galvanized steel, and cast iron. Call for availability. Catch Basins. Load class A rating; Grate open area of 70%; Grate openings 1. 00. 25″ x 1. Selecting the appropriate Load Class is another important aspect of installing a trench drain system. The locking system consists of two locking bars and two screws per section. This slotted grate measures 24″W x 24″L. 21. In addition to its versatility, with precision pre-casting, you get a high-quality pre-sloped drainage channel product that requires less onsite labor. LOAD CLASS B - 28,101 LBS - 125 KN (387–580 PSI) Sidewalks and small private parking lots LOAD CLASS C - 56,202 LBS - 250 KN (774–1,160 PSI) Parking lots and general commercial areas LOAD CLASS D - 89,924 LBS - 400 KN (1,238–1,856 PSI) Trafficked sections of roads and highways LOAD CLASS E - 134,885 LBS - 600 KN (1,856–2,785 PSI) Heel Proof Rated - Grate's slot width does not exceed 5/16 Inch. DI Ductile Iron - Rust-Resistant Oil-Black 24" Class E* 30. These grates are. The Dura Trench grates are 40% to 75% thicker than competing stamped metal trench drain grates. Grates. Car and light vehicle traffic at less Class A Load Rating (1-60 PSI) Use With NDS Slim Channel Drain; Recommended for pedestrians, bicycles, and wheelchair traffic; Heel-Proof; Made from UV Protected Material; NOTE: Couplers must be ordered separately. Load Class A can support from 1 to 160 pounds per square inch. specification A-240, (type 304), is rated class A per the DIN EN1433 top load classification. System: MAX Mini, Mini Channel. maximum safe live load is computed by dividing the load at failure by two. (Approximate nominal wheel load 330kg) Load Class B Footpaths, car parks and residential properties (Approximate nominal wheel load 2,670kg) Load Class CThe ACO K100 Trench Drain is uniquely designed to install and perform at the highest levels. POLYCAST 500 Kit w/ Stainless Steel Edging and DG0631 Transverse Slotted Grate | Class A. . Grate Design: Safety. Channel Material: Polymer Concrete. Trench drain systems are available for any trench drainage applications. System shall be frame-anchored, with (specify) grating to suit DIN Class (specify) load rating. Load Class: Provide trench drain system designed, engineered and installed to support the minimum loads as defined by. VEVOR Trench Drain System, Channel Drain with Metal Grate, 5. C grates support loads of at least 56,200 pounds per square foot. p. The end outlet can be configured for 6″ 8″ and 12″ pipe. Filter. Your #1 Trench Drain Supply Resource! Manufacturer: ULMA. A system should have grating that will not warp or break from the traffic driving over it. Load class is an important factor in driveway drains. U. Popular Sizes. Load Class plays a large part in how durable the drainage system is. Load Class B. The 6″ Dura Slope by NDS® is one of the most customizable plastic trench drains available for commercial projects. 5-3/8 in. Heavy Duty Ductile Iron Slotted Class E (122mm x 498 mm) Add to cart. Slots measure 1-1/4″ wide. Grates are secured with QuickLok locking mechanisms. Specification Sheet. Trench Era FF Series Drain System w/FG1244 14″ Wide Class C Grate – Stainless Frame $ 3,287. Perforated Galvanized Steel Mesh Galvanized Steel Slotted Galvanized Steel Combee Composite Honeycomb Longitudinal Bar. The ZURN Z884 4. Current DIN/EN Load Classifications for Trench Drain Grates are: DIN CLASS A Residential and Light Pedestrian Traffic DIN CLASS B Sidewalks, Private Parking Lots. The longitudinal slots are in the same direction as the trench. Call us at 610-882-3630 for help in finding the right replacement lids!Trench Drain FAQ. ada compliant for accessible routes. These grates are perfect for any medium-load and pedestrian applications such as: Driveways. This trench drain grate is MADE IN THE USA and meets Class A Load Requirements for Light-Duty Loads, is ADA Compliant and Heel-Proof. 29 GPM) per foot. System numbering - Each end of the channel indicates the number of the channel that will connect to it. A discreet drainage solution for use with brick or stone pavers. The NDS Dura Slope trench drain system consists of neutral and pre-sloped sections of trench drain. com or DrainageKits. 105″ thk). Phone: 610-882-3630. Cast iron heavy-duty grate. 2. Heavy duty trench drains - boltless grates. 25″ width and a length of 12″. Class D grates support loads of at least 89,920 pounds per square foot. 4. Application: Patio, Pool and Spa, Poolside, Residential. 12" Wide Zurn Z882 Heavy Duty Trench Drain Kit C Class Grate NEW Zurn Z882 Heavy Duty Trench Drain 12 Inch Wide - Ductile Iron Frame and C Class. 4" B Class Decorative Botanical Trench Drain Grate Gray HDPE - Load Class B - Fits NDS Spee-D Trench Drain Product Dimensions: 4 1/8"W x 24"L x 3/4"D. Load Class C - Commercial vehicle traffic, residential vehicle parking, buses, and medium duty commercial equipment. 3 out of 5 stars 25This P12-HPD Ductile Iron Grate measures 11. Zurn Z883 Shallow Trench Drain By Item; Zurn Z874 Series Trench Drain System; Zurn Z800 Series Fiberglass Trench Drain System;. Comes with multiple grate options. ACO SlabDrain – Steel Edge provides systems up to and including load class E. Instead, this modular system uses interlocking 0. The trench, usually made of materials like concrete, captures surface water. Class B Load Requirements for Light Loads and is ADA compliant. Grate Shape: Rectangle. Grate Width: 6 inch. Load Class is a fundamental aspect when choosing a drain system and its grating. Poor site conditions and low load bearing pavement will require an increase in these dimensions to meet both vertical and lateral loads. Floor drain grates mount over openings like floor. S300K. Load class C 56,200 Lbs per foot (250 kn). Phone: 610-882-3630. We also have three fabrication material options: stainless steel, galvanized steel, and cast iron. Appropriate sealant can be used to create a sealed joint. Load Class D - Heavy duty trucks, gas stations, forklifts, highways. Extra Heavy-Duty Floor Drain Grates (Class D) Extra heavy-duty floor drain grates filter out large particles and allow wastewater to flow freely into drainage systems. Concrete pavement - load class A-F . Bottom ‘ leveling feet’ can be ground for proper height adjustment. Regular trench drains run from around 4 1/2” deep to upwards of 17” deep. 4 in. Class B ____ -RFG Reinforced Galvanized Steel Slotted Grate -. 9665 9665 MD MD MD B 12-14-10 s9665 CL Anchor Flange or Flashing Flange/Clamp (When Specified) 2. Durable polypropylene frames for light & moderate traffic. Order online, or call TDS at 610-882-3630. Applications; Technical; Service; About Us. Grate Load Class: Class D. (125 kn). General Purpose Drainage Interior with a full range of Linear Trench Drains provides you with full list of features and benefits. It is ideally suited for aLoad Class. Lockable grates are boltless for easy maintenance. specification A-240, (type 304), is rated class A per the DIN EN1433 top load classification. 5″) Grate depth 1. Grate Material: Ductile/Cast Iron. This standard classifies the loads in a alphanumeric format ranging from A through F. Our selection includes encased grates, raw grates, dome grates, precast grates, road gully grates, and more, all made from high-quality materials that offer superior durability and resistance to. System to include frame connectors, grate. primarily for floor drains and does not effectively address linear trench drains. ACO 100 (39) Per Page. 80″) wide and 0. Grate actual dimensions: 5-3/8″W x 20″L x 3/4″H. Fort Carson. This PDF provides detailed information on product features, dimensions, performance, and accessories for. Popular Manufacturers. This grate has a Load Class B rating and fits the same Spee-D channel drain sold at the major home improvement box stores. 1. DG0641D 6" E Class Ductile Iron Slotted Trench Drain Grate Ductile Iron - Load Class E - FitsPolycast 500/600/700 Series. Manufactured from HDPE, this trench drain offers a durable alternative to concrete channel that will save time and reduce cost at installation. The water then flows into the channel and is directed away from the area, preventing water accumulation. Grates that comply with requirements of the Americans with Disabilities Act. Load class E - Industrial areas, gas stations and light commercial forklifts Load class F - Aircraft pavements, docks, heavy fork trucks and heavy wheel loads. , 600kN, 2785 PSI. Stainless Steel Grate Specs. Channels are offered in 1-meter sections. Ideal for residential, commercial and industrial applications: Driveways. TDS DG3048R Class C BAR Galvanized 8″ x. Systems are available in a variety of widths, depths, lengths and load ratings suitable for urban pavements and protecting buildings from stormwater. Weight load up to 3,372 lbs. Perforated metal grate, pedestrian traffic rated, heelproof, ADA compliant. Proof load test is the recommended method for determining a casting’s load performance. Call our experts today for a fast quote. The K50, K100, K200 and K300 respectively. Light-Duty Floor Drain Grates (Class A) Rectangular, sorted by Material, custom. Grate Design: Safety. The fundamentals aspects of the test are: A specified load is applied over a 9″ x 9″ contact area at the center of the casting. SKU: 05AF24BPB. The 200 series consists of 33 pre sloped channels and 8 neutral channels. Specifying and purchasing a water runoff control system has been made simple with driveway drainage. Load class E - Industrial areas, gas stations and light commercial forklifts Load class F - Aircraft pavements, docks, heavy fork trucks and heavy wheel loads. The square galvanized steel grate from NDS® is ideal for yard drains to collect surface water and minimizing the amount of debris that enters the system. Galv. Affects grate load class, channel edge detail and installation details. When choosing the right outdoor trench drain one of the most important factors to consider is load rating or how much weight is expected to be applied on the drain. Filter. Trench drains and catch basins are used to divert and carry water runoff away from the site. This rust- and corrosion-resistant galvanized steel grate can be used with the 12 inch NDS catch basin, riser, or low. We manufacture trench drains for load class A, B, C, D, E,. usa@bg-graspointner. 21. Load class E - Industrial areas, gas stations and light commercial forklifts Load class F - Aircraft pavements, docks, heavy fork trucks and heavy wheel loads. 6" B Class ADA HDPE Trench Drain Grate Brick Red HDPE - Load Class B - Fits NDS Dura Slope Trench Drain Product Dimensions: 6"W x 24"L x 3/4"D Submittal: NDS 660-665 Specification. TRENCH DRAIN KITS & FRAMES POLYCAST® | SYSTEM | LOAD CLASSIFICATIONS CHART 800. Contact us for a free quote or for further information on drainage solutions visit TrenchDrain. Optimized channel shape ensures improved discharge rates even for low water levels and enhanced self-cleaning effect. Polymer concrete drainage channels also feature tongue and groove joints for positive alignment and an outstanding fit with any requisite joint sealant. Grate Width: 2 inch. Ductile Iron Grate Specs. The NDS Dura Slope trench drain system consists of neutral and pre-sloped sections of trench drain. Co. Phone: 610-882-3630. Channel slopes can also be adapted to fit. Load Class C - Commercial vehicle traffic, residential vehicle parking, buses, and medium duty commercial equipment. Add to cart. Trench Drain. These heelproof snap-on galvanized steel mesh grates fit class B medium-duty trench drain applications where water drainage is needed. Iron Age IA-LOC-0520 Class B Locust Cast Iron 122mm x 500mm Grate – RAW $ 153. The serviceability load is set at 2/3 of the ultimate limit state design load. 6 Inch Square Grate, Square Opening with Adapter 637 638 639. Your #1 Trench Drain Supply Resource! Grate Shape: Rectangle. Load Class shall be: _____. PDF. System: Frame and Grate, Trench Era. NDS channel and trench drains are designed for durability, drainage. POLYCAST 500 Series Kit with DG0640 Slotted Galvanized Grate | Load Class B. Excavate the trench Prepare the trench for the Polymer Concrete Channel with appropriate concrete-surround by load class as detailed by the Engineer on record: Light and medium duty Heavy and special duty. Pre sloped at 1%. Please note that all raw cast iron grates begin to naturally rust with exposure to any form of moisture and will appear bright orange before settling to brown. (Load Classifications are per DIN EN 1433) ____ -AWG Aluminum Wire Grate - Class A. More Details. Interlaken Heel Proof pattern is available in either the raw casting or Baked on Oil Finish (BoOF). Gray. You need to assign Widgets to "Shop Sidebar" in Appearance > Widgets to show anything here. Load Class A - pedestrian foot traffic . Class E must be achieved on urban freeways/highways. Add to cart. The system can be extended upwards of 196 linear feet. With our BG-FILCOTEN® pro V channel, you don’t have to compromise on quality or durability. Plastic (structural foam polyolefin) meets Class B load rating (61-175 psi), while ductile iron and cast iron meet Class D load rating (326-575 psi). H-20 Load Rated. Description. Typical vehicle speed. 6. 5″) Grate depth 1. Load Class. com. Trench Drain Systems offers an extensive line of trench drain channels, grates and catch basins including decorative options: Exclusive product lines manufactured by TDS. Trench drainage products available for any trench drainage applications. Add to cart. Notes. Four screw holes per grate for NDS529 fasteners (not included). Load Class E - Extra heavy duty, hard tire forklifts, industrial areas,. 6" Decorative Grates. Because of its. 48 – $ 1,377. It is important to ensure that this system is working properly. Grate Width: 12 inch. Trench Drain Project Sheet; Revit models – BIM data; BG-FILCOTEN. Load Class B - Residential vehicle traffic (no parking) and yard equipment . Easier and cheaper to install than concrete products. Load Class: Provide trench drain system designed, engineered and installed to support the minimum loads as defined by. 6. UV inhibitors in the grate prevent fading and cracking from the sun. CastSlot is available with a 30mm opening and a Treadsafe. Add to cart. Load Class C - Commercial vehicle traffic, residential vehicle parking, buses, and medium duty commercial equipment. MIFAB, Inc. POLYCAST® | SYSTEM | LOAD CLASSIFICATIONS. PowerDrain S300K. Using an inferior Load Class than required can lead to a failed and possibly damaged system. This testing procedure is detailed in Federal Specification CID A-A 60005 and AASHTO M 306. Stainless steel is ideal for basic pedestrian traffic, and our ductile cast iron is built for heavy-duty, C-Class loads. All trench drain grates have safe live load. Installer Map; Virtual Trade Show Room; Testimonials; Trench Drain Glossary; Drainage News; Drainage Shop. Includes: 6 channels (40″ sections), 12 cast iron grates (20″ sections), 1 end cap and 1 end outlet. Available in 2 finishes: Smooth or an embossed diamond tread surface for slip resistance. Your #1 Trench Drain Supply Resource! Grate Shape: Rectangle. For more info on load classes click on the link: Available load classes for our 4" Base plastic trench drain: Load Class A - pedestrian foot traffic. Load Class: Provide trench drain system designed, engineered and installed to support the minimum loads. Founded in 1998, Eric'sons is the manufacturer of Dura-Trench trench drain and specializes in a Quick & EasyTM system. FILCOTEN® pro E trench drain is available in stainless steel rails up to class E 600 (acc. B. Excavate trench to accommodate the drain system. 1M and DIN 19580. Fiber concrete channels with galvinized steel frames. 5offers a wide range of grates for applications from Load Class A to Load Class F. Round Catch Basins Channel Drains Valve & Meter Boxes Square Catch. 89. Specs and Installation. Dura Trench manufactures a wide array of sizes of prefabricated catch basins from a wide variety of materials. Reinforcing steel may be required within the slab and around the trench drain - engineering advice should be sought to determine bar size and configuration. Load class is an important factor in driveway drains. Heavy-duty trench drains, all sizes. A. 1. This will have a large impact on the life of both the channel drain and grating. Designed for handling a high load capacity, Swiftdrain is a smart choice for industrial settings like parking lots, garages, and factories. * Load class ratings for entire systems will always be determined by the lowest class within the system. This eye-catching metal grate is exclusively made and offered by Trench Drain Systems and measures 2. L Trench and Channel Drain Kit with Black Grate (3-Pack : 9. Dynamic Load Rated - Grates, rails, frames, and grate retention are designed for 0. TDS FG1245 Class A Mesh Fiberglass 14″ x 48″ Grate. Mascot Engineering is a founding member of the Grates & Access Covers Alliance (GACA) and. 6 of the ANSI Standard) between 5,000 lbs. 5-inch Wide Trench Drain Solid Cover | Medium duty black powder-coated steel. ANSI A112. Supplies and solutions for every industry, plus easy ordering, fast delivery and 24/7 customer support. Slim Channel Accessories Spec Sheet SKU: 05AF24BPB. 2 foot kits are intended to be an extension to kits and only include one install chair and no end caps/outlets. A. 4" Trench Drains BG-FILCOTEN Tec V 100 by NDS® trench drain system is available with galvanized or stainless steel rails in pre-sloped and neutral sections and is resilient up to Class E600 (in accordance to DIN 19580). 5″ x 1. Floor drain grates mount over openings like floor drains, trench drains, sanitary and sump drains, and floor sinks to allow water and liquids to flow through them but trap larger objects and debris to prevent clogs. New. – Load class: light to extra heavy duty (A15 to E600) – Sizing: NW150 to NW300 (6”-12” or 150-300 mm)Description. For commercial pneumatic tire traffic patterns, forklifts and tractor trailers. Load class D 89,920 Lbs per foot (400 kn). 00. 6" Galvanized Ductile Iron Slotted Grate. Load Class. Load class up to D400. Rated as a Load Class B, it is also ideal for light pneumatic tires traffic, pedestrian applications, sidewalks and residential parking. Structural foam Polyolefin slotted grate for the NDS® Dura Slope trench drain system. 1M:. Weight load up to 28,100 lbs Load Class C Trench Drains - Class C trench. Courtyards. Because of its application, 150 psi is needed with a maximum proof load of 12,150 pounds. When it comes to standards, it falls under light pneumatic tire traffic. The recognised international standard relating to modular channel drainage systems is the European Standard EN 1433:2002 – drainage channels for vehicular and pedestrian areas. Click here for more info. Application: Greenhouse, Municipal, Patio, Pool & Spa, Poolside, Residential. Description. Load Class B - Medium duty traffic, light vehicles, sidewalks and residential parking. FILCOTEN Pro V 300 Channel 3 with Galvanized Rail SKU # 10630203. Channel Number. Grate ID. Grate Load Class: Class B. Heavy Duty. 6" B Class ADA HDPE Trench Drain Grate Sand HDPE - Load Class B - Fits NDS Dura Slope Trench Drain Product Dimensions: 6"W x 24"L x 3/4"D Submittal: NDS 660-665 Specification $53. skip to Main Content. Please note that all raw cast iron grates begin to naturally rust with exposure to any form of moisture and will appear bright orange before settling to brown. 25″ wide polymer concrete channel with DG0641D ductile iron slotted grate. Secured channel grate. 1321 West 119th StreetThis extensive grate range is available with ACO’s precast modular Polycrete ® Channels and stainless steel trench drains. Most commonly used with Dura Trench 4 ” wide prefabricated trench drain. $ 101. Dimension(s): 4' L x 6"W x 5" - 5. Related products . Download our drainage product guide to learn more about our trench drains, slot drains, area drains, and accessories. Rated for DIN load class B. Deep Seated Anchorage Bays. KlassikDrain is sold as channel only. Load Class: B Load Class: C product dimension product # lbs/ description [inches] unit Slotted ductile iron grating 19. A complete line of trench drainage products engineered for easy layout and installation providing ideal solution to your unique needs. Industrial trench drains are designed to handle the toughest applications. Add to cart. Products. Browse a wide range of replacement Trench Drain Grates from Load Classes A-F. can I cut a drain trench out of the blacktop where it meets the concrete put this drain system in and backfill with gravel/crushed rock or does it need to be cemented in? A: A cut can be made in. Durably made from HDPE, the NDS Dura Slope system offers the strength of a concrete trench system without the costly installation. Additional information. $ 429. 01. Load class E - Industrial areas, gas stations and light commercial forklifts Load class F - Aircraft pavements, docks, heavy fork trucks and heavy wheel loads. FG-HLC-0848 Mesh Fiberglass 8″X48″ Grate Load Class C. DI Ductile Iron - Rust-Resistant Oil-Black 24" Class E* 30. For more info on load classes click on the link:Channel drains, also known as trench drains, are long, narrow drains that collect water and direct it to drain pipe; the water is carried to a discharge point downstream such as a pop-up emitter or to percolate into the ground with a dry well or infiltration trench. S. Catch Basin Kits; Catch Basin Grates. Contact us for a free quote or for further information on drainage solutions visit TrenchDrain. To make Dura Trench stamped grates the best on the market we have made our grates from 12 gauge metal (0. Engineers grade loads from A to E. Load class E - Industrial areas, gas stations and light commercial forklifts Load class F - Aircraft pavements, docks, heavy fork trucks and heavy wheel loads. 5″ * Load class ratings for entire systems will always be determined by the lowest class within the system. 813″ x 19. 200mm DrainLok Trench Drain Grates by Load 200mm grates. T100-PGB-13-LS Galvanized Longitudinal Grate. 0% N N GS Galvanized Steel Slotted 48" Class B 23. Product type and width e. Download S200K Spec Info. (125 kn). Manufactured from HDPE, this trench drain offers a durable alternative to concrete channel that will save time and reduce cost at installation. B 125 kN, galvanized (tec, pro) tec E, V / pro G, E, V. Load Class A Trench Drains - Class A trench drains handle the lightest loads. KlassikDrain (with removable grates) Features & benefits;. The table below shows different drainage load classes and typical uses for ACO drainage channels that are CE marked and fully certified to Load Class BS EN 1433:2002. Supplied in 40” [1016mm] nominal lengths with 5/16” [8mm] wide slots, and 3/4” [19mm] bearing depth. 2 requirements for a W80 wheel load. Channel Body and edge made entirely in innovative SMC/GRB. Type of vehicle – to determine the load class. Paver pavement - load class A-E. 74. Class B grates (cars and lightweight trucks) or class C grates (heavy-duty traffic, H-20 loading) are recommended. 00. Dimension(s): 4' L x 6"W x 5. Class A Loads up to 3,372 LBS Pedestrian traffic. These grates are built to support pedestrian traffic only and are available in different materials, and come in distinct shapes, sizes, and colors based on specified applications. 01%. All Load Class B: EN 1433 - 28,100 lbs. Email: Shop@TrenchDrain. C. 4. 1 – Light Duty - All grates having safe live load (as calculated in para.