PAES 121:2001 - Agricultural Disc Plow Standards

• The Philippine Agricultural Engineering Standard PAES 121:2001 covers specifications for agricultural machinery, specifically disc plows.
• The national standard's formulation was initiated by the Agricultural Machinery Testing and Evaluation Center (AMTEC).
• The "Enhancing the Implementation of AFMA Through Improved Agricultural Engineering Standards" project funded this standard.
• The Bureau of Agricultural Research (BAR) of the Department of Agriculture (DA) funded the project.
• PNS 01-4:1998 (ISO/IEC Directives Part 3:1997) guides the structure and drafting this standard.
• The standard complies with metrication law "Batas Pambansa Bilang 8," enacted on January 1, 1983, converting some data to the International System of Units (SI).
• The word "shall" indicates strictly followed requirements without deviations.
• The word "should" indicates a recommended possibility that isn't necessarily required.
• The standard considers documents/publications from ASAE, Albert Boers, Stevens G.N., and RNAM.
• This standard specifies requirements for disc plows used with four-wheel tractors.
• ISO 730-1:1994/Cor 1:1995, "Agricultural Wheeled Tractors – Rear-mounted three-point linkage - Categories 1, 2, 3 and 4" contains provisions that constitute this standard.

Definitions

• Concave disc: A circular concave steel plate used for cutting and inverting soil.
• Concavity: Vertical distance from the lowest point to the center of the disc when its concave side is on a flat surface.
• Disc plow: Implement with individually mounted concave disc blades to cut, invert, and pulverize soil. Blades attach tilted to the frame relative to direction for penetration and soil displacement.
• Frame: The structure on which the standards are fitted.
• Hitch: Portion of an implement designed to connect the implement to a power source.
• Scraper: Component that scrapes the soil adhering to the concave side of the disc.
• Side angle/Disc angle: Angle in the soil surface plane, between a tool axis and a line perpendicular to the direction of travel.
• Standard/Beam: Upright support connecting the shank to the tillage implement frame.
• Tilt angle: Angle in a vertical plane perpendicular to the direction of travel, between a tool axis and the soil surface.
• Width of cut: Transverse distance between either the top or bottom cutting edges of the end discs. Tilt angle is set to 15 to 25 degrees for measuring width and 18 to 20 degrees for non-adjustable blades.

Classification

• One-way disc plows: Tractor-mounted or integral, attached by three-point hitch linkages, and fully carried during transport.
• Reversible disc plows: Attached to the three-point hitch and carried by the tractor. Limited to 2-4 discs due to tractor stability and lift capacity.
• Semi-mounted/Semi-integral reversible disc plow: Attached to the tractor's lower hitch points, raised/lowered by tractor hitch and a remote hydraulic cylinder on the rear transport wheel; the rear wheel serves as gauge/transport wheel.

Size and Materials

• Plow size is determined by the number and diameter of discs and the width of cut.
• The formula to calculate the width of the cut is W = (0.95NS + 0.3D) / 1000, where W is width of cut (m), N is the number of discs, S is the disc spacing (mm), and D is the disc diameter (mm).
• Mild steel is used for the frame, scraper, thrust wheel, and hitch.
• Cast iron is used for the spool's manufacture.
• Carbon steel is used for the hitch pin.
• Disc blades use carbon steel (at least 0.80% carbon, e.g., AISI 1080) or alloy steel (at least 0.0005% boron).
• High carbon steel is used for the standard.

Construction Requirements

• Disc plows must adhere to specific construction requirements and have either plain or notched discs.
• The number of discs ranges from 2 to 8.
• Disc diameters range from 560 to 810 mm.
• Working widths range from 500 to 2000 mm.
• Working depths range from 200 to 400 mm.
• Frame heights range from 650 to 800 mm.
• Disc spacing varies from 500 to 750 mm.
• Weight per disc ranges from 150 to 250 kg. Drawbar power requirement per disc should be 15 to 20 kW.
• Disc thickness varies with diameter, ranging from 4 to 6 mm for 560/610 mm discs to 8 to 12 mm for 810 mm discs.
• Disc concavity varies with diameter, ranging from 60 to 92 mm for 560 mm discs to 104 to 144 mm for 810 mm discs.

Performance, Other, and General Requirements

• The plow should attain the maximum depth of cut specified.
• The plow should produce good quality work, inverting plant residues and providing uniform soil clods.
• Each disc should be securely fastened to the hub with four or five plow bolts.
• The frame must be rigid and durable.
• Adjustable scrapers should not touch the disc face and should effectively scrape soil.
• Grease points for bearing lubrication, proper alignment, and dirt seals are needed.
• The disc plow hitch must be compatible with the hydraulic system and three-point hitch specified in PAES 118.
• The plow should be easy to hitch/unhitch, adjust depth, change position, move standards, maneuver, clear blockages, change position, and adjust scrapers.
• The disc plow should be free from manufacturing defects and rust (except for disc blades) and properly painted.
• The disc plow (except disc blades) should lack sharp edges that may injure the operator.

Warranty, Maintenance, Labeling

• A warranty against defects in materials/workmanship should be provided for parts/services (except consumable parts) within 6 months of purchase.
• The construction should be rigid and durable without major component breakdown within 6 months of purchase.
• A set of tools for field adjustments and an operator's manual conforming to PAES 102 shall be provided.
• Each plow shall be marked in English with the manufacturer's trademark, brand, model, type/size, serial number, production date (optional), manufacturer/importer name and address (optional), country of manufacture/ "Made in the Philippines", and safety markings.