A06 Specifications Workmanship.pdf

HIF-W-01C

09-09-10

U.S. Geological Survey Water Resources Division

HIF Specification

WORKMANSHIP

1. Purpose.

This specification establishes the acceptable workmanship criteria for equipment intended for use by the U.S. Geological Survey, Water Resources Division.

This specification will define those workmanship requirements not normally covered in subsidiary specifications or drawings. It is not intended to supersede any of the provisions of the contract or applicable specifications and drawings considered a part of the contract. Where actual conflict exists, the provisions of the contract or applicable specification or drawing shall take precedence over the requirement herein.

2. General.

Workmanship shall be in accordance with the requirements herein and any requirements of the detail equipment specification applicable to soldering, marking of parts and assemblies, wiring, welding and brazing, plating, riveting, finishes, machine operations, screw assemblies, and freedom of parts from burrs, sharp edges, or any other damage or defect that could make the part (or equipment) unsatisfactory for the purposes intended.

(a) Surface defects.

(b)

The finished surfaces shall be free from dents, scratches, nicks, cracks, splits, perforations, pits, porosity, or other such surface defects.

Burrs.

(c)

No part shall have a burr, or nonfunctional sharp edge or corner which might interfere with the assembly or function of the item or which might be injurious to personnel handling the item.

Corrosion

(d)

No part shall contain any rust, oxidation, scales, or other such corrosion products.

Extraneous materials.

(e)

No part shall contain any extraneous materials or foreign matter such as dirt, grease, oil, or chips.

Markings.

All specified markings shall be neat and sharply defined.

There shall be no unspecified markings.

3. Mounting of parts. Parts or hardware shall be assembled and secured or mounted in the specified manner to satisfactorily accomplish the purpose for which intended, and shall, wherever practicable, be so mounted that values and part numbers containing values are visible. The use of automatic insertion equipment is an example where control of part value visibility and orientation may not be practicable. Terminal designations of trans-formers, inductors, relays, etc., shall be visible to facilitate repair. Equipment having hrmyers Highlight missing, inoperative, defective, bent, broken, or otherwise damaged parts will not be acceptable.

3.1 Mounted hardware installation.

The installation of hardware parts, such as hinges, catches, handles, or knobs, shall be accomplished in such manner as to avoid dam-aging the hardware or the mounting surface. Hardware or mounting surfaces damaged in this way shall be touched up to provide a continuous protective coating. A color match between the surface touched up and the original finish shall be provided.

4. Cleaning.

After fabrication, parts and assembled equipment shall be cleaned of smudges;

loose, spattered, or excess solder; weld metal; metal chips and mold release agents or any other foreign material which might detract from the intended operation, function, or appearance of the equipment. (This would include any particles that could loosen or become dislodged during the normal expected life of the equipment). All corrosive mate-rial shall be removed. Whenever possible, this cleaning shall take place before the parts are assembled into the equipment. All assembled equipment shall be cleaned of contami-nants such as lubricating oils (unless otherwise required), mold release agents, waxes, sand, corrosion products, solder fluxes, finger prints, dust, etc. The nature of the contaminant must be determined to the extent that a suitable cleaning solvent can be selected for item removal. The inertness of the materials of construction to the solvent must be determined to prevent damage to electrical and mechanical properties. After cleaning, moving parts should be relubricated and the assembly allowed to dry to remove trapped or soaked cleaning fluid. Cleaning processes shall have no deleterious effect on the equipment or parts.

5. Threaded parts or devices.

Screws, nuts and bolts shall show no evidence of cross thread-ing, mutilation, or detrimental or hazardous burrs.

5.1 Tightness.

All screw-type fasteners shall be tight. The word tight means the screw shall be firmly secured and that there shall be no relative movement possible between the attached parts.

6. Riveting.

The riveting operation shall be carefully performed in order to assure that rivets are tight and satisfactorily headed with the rivet heads tightly seated against their bearing surface.

7. Gear assemblies.

Gear assemblies shall be aligned and meshed and shall be operable without interference, tight spots, loose spots, excessive backlash, or other irregularities that could cause unsatisfactory operation.

8. Bearing assemblies. Bearing assemblies shall be free of rust, discoloration, and imperfec-tions of ground, honed, or lapped surfaces. Contacting surfaces shall be free of tool marks, gouge marks, nicks, or other surface-type defects. There shall be no detrimental interference, binding, or galling.

9. Wiring.

Insulated wire running between equipments or subassemblies within an equip-ment, such as between drawers or chassis and module subassemblies, shall be formed into cables or ducted wherever practicable. Wires and cables shall be positioned or protected to avoid contact with rough or irregular surfaces and sharp edges.

9.1 Wire dress or cabling of wires shall not result in improper electrical operation or interference with mechanical operation that will lead to subsequent damage of the wire or cable. Wires and cables subject to flexing shall be protected to prevent abrasion.

9.2 Lacing of cabling shall be neat in appearance. The lacing shall be applied firmly, yet not with excessive pressure which could cut into conductor insulation.

9.3 Cabling or wiring harnesses shall be anchored to avoid damage to conductors or adjacent parts. Strain relief shall be provided for external cabling.

9.4 Insulation.

There shall be no evidence of burns, abrading, or pinch marks in the insulation that could cause short circuits or leakage.

9.5 Splicing.

Wires in a continuous run between two terminals shall not be spliced during the assembly of the equipment, except where a stranded conductor is spliced to a solid conductor and the two are supported at the splice.

9.6 Clearance.

The clearance between wires or cables and heat generating parts, such as electron tubes and resistors, shall be such as to avoid deterioration of the wires or cables from the heat dissipated by these parts under the specified service condi-tions of the equipment.

9.7 Shielding.

Shielding on wires and cables shall be secured in a manner that will prevent it from contacting or shorting exposed current-carrying parts. The shield-ing shall terminate at sufficient distance from the exposed conductors of the cable to prevent shorting or arcing between the cable conductor and the shielding. The ends of the shielding or braid shall be secured against fraying.

10. Welding and brazing.

All welds and brazes shall be free of harmful defects such as cracks, porosity, undercuts, voids, and gaps. There shall be no burn-through. Fillets shall be uniform and smooth. Angular or thickness misalignment, warpage, or dimensional change due to heat from the operation shall be within permitted tolerances. There shall be no damage to adjacent parts resulting form the welding or brazing.

11. Ropes and cables.

All ropes, cables, and their jackets shall be free from such braiding defects such as knots, kinks, and snags. The cables with cloth jackets shall be kept clean and free of dirt, grease, wax, or other contaminants.