Porcelain Enamel Signs on Steel, ZD
  1. Scope. This specification covers signs used to identify transmission towers, to color-code and identify phases and to warn individuals that they should keep out of high voltage equipment.
  2. Material. The base material shall be a decarborized enameling sheet steel. The thickness and weight of the base steel shall be:
     
    3. Pounds Thickness in Mils Pounds Square Foot

    24

    23.9

    1.00

    18

    47.8

    2.00

    16

    59.8

    2.50

    14

    74.7

    3.13

 

  1. Porcelain Enamel Frit. The base steel shall be properly cleaned and coated with a ground coat having a minimum thickness of 0.002". The ground coat should then be covered with a base white coat having a minimum thickness of 0.005". The frit shall be fired at 1,400-1,500ºF. Signs shall be made in accordance with the following specifications:
  • Porcelain Enamel Institute Bulletin P-302, "Manual Dipping and Flow Coating for Porcelain Enameling"
  • Porcelain Enamel Institute Bulletin P-307, "Preparation of Sheet Steel for Porcelain Enameling"
  • Porcelain Enamel Institute ("PEI") Bulletin P-313, "Special Finishes for Porcelain Enameling"
  • ASTM A424, "Sheet Steel for Porcelain Enameling".
  1. Physical Characteristics. The sign shall have the following characteristics:
     
    2. Property Results
    Tensile Strength (ASTM D882) 27,000 psi
    Porcelain Gloss (ASTM C540) at least 50 at 45º
    Dielectric Strength (ASTM D149) 200 volts/mil of P/E
    Operating Temperature -50ºF to 1,500ºF

 

  1. Izod Impact Test. The sign shall withstand an Izod Impact test of 55 inch pounds (ASTM C988) with minimum cracking or damage.
  2. Chemical Resistance. The material shall have the following resistance to exposure using DIN 42 115 Part 2:
     
    3. Chemical Rating
    Acids excellent
    Alkalines & Salt excellent
    Water excellent
    Solvents excellent

 

  1. Weathering. A sign sample shall be weathered using ASTM D4329 and UVA 340 lamps. After 20,000 hours of exposure in a QUV weathering deck the sign shall remain readable. Sample of weathered and printed sign shall remain on file at the manufacturer and is available for review by the customer.
  2. Eyelets. Brass, non-corrosive eyelets shall be used in the holes of the sign. The eyelets shall be formed in the holes after the porcelain enameling is complete. The eyelets shall have a 0.25" id.
  3. Printing & Processing. Ciba-Geigy Porcelain Enamel screen printing pastes shall be used. The printing type style shall be Clearview. The colors used shall be as follows:
  4. Size. & Holes The signs shall have the following dimensions:

    5. 7" x 10"
    10" x 14"
    14" x 20"
    The centerline of each hole shall be 375" from the outside edge.

  5. Fence Clips [optional]. For signs that will be hung on a fence, the sign shall be provided with [two, four] aluminum fence clips. The holes in the sign shall be spaced so that the fence clips will properly align themselves to the standard diamond repeat of the chain-link fence, including allowable deviations. Typically, the centerline of the holes shall be spaced 3-1/2" apart. The fence clip shall be fabricated from a 0.090" thick aluminum and a 1/4-20 locking PEM insert. Tamper-proof bolts shall be provided for each hole.
  6. Packaging. Each box of signs shall contain only one sign design. No one box shall weigh over 70 pounds. Quantities of 25 or more signs shall be packaged in a wooden crate.
  7. Warranty. Workmanship and quality shall be such that all lettering is sharp, legible, straight, and aligned properly. Smudges, misalignment, miss-wording, misspelling, crooked letters, incorrect color, incorrect materials, and any other problems that show poor quality and workmanship will give sufficient cause to reject any sign. The signs are to be guaranteed by the vendor to be free of workmanship or material defect. If, for reasons of workmanship or material defect, the sign becomes unreadable during a period of twenty years, the vendor shall replace the sign at no additional charge.

 

ELECTROMARK'S OBLIGATION UNDER THIS WARRANTY IS LIMITED TO REPLACEMENT OF THE PRODUCT. OUR PRODUCT IS SOLD WITHOUT ANY WARRANTY OF MERCHANTABILITY AND WITHOUT ANY WARRANTY THAT OUR PRODUCT IS GOOD FOR ANY PARTICULAR PURPOSE. OUR PRODUCTS ARE SOLD WITH THE UNDERSTANDING THAT THE USER WILL DETERMINE THEIR ADAPTABILITY FOR HIS INTENDED USES. WE ARE NOT BOUND BY ANY OTHER WARRANTY, EXPRESSED OR IMPLIED. UNDER NO CIRCUMSTANCES ARE WE LIABLE FOR ANY LOSS, DAMAGE, EXPENSE OR CONSEQUENTIAL DAMAGES OF ANY KIND ARISING OUT OF THE USE OR INABILITY TO USE OUR PRODUCTS.