Document QmOzQeGDXR5G7kEYZL1q71jo

ALCOA Engineering Standard Mechanical MATERIAL HANDLING SLINGS 15.1 1991 JULY PAGE 1 1. SCOPE This Standard provides the specifications to be used in ordering, using, and maintaining chain, wire rope, and synthetic webbing slings. The present Standards are being replaced effective the date of this standard: o 15.1.1 o 15.1.2 o 15.1.3 Chain Slings dated July,1962. Wire Rope Slings dated June,1981. Synthetic Webbing Slings of ttylon and Polyester dated January, 1973 Use ANSI/ASME B30.9 Slings, as the new reference for all specifications and recommendations for application. The current publication and/or addendum will be used unless otherwise indicated. SUPERSEDES 1988-DECEMBER 4683461524 5 Thlt engineering atenderd I t provided aolely lor the purpot* of dltclotlng A tcot't approach end I t noi Intended to to e recommendation for any recipient other then Alcoa. No wvmmles, guarantees or representations, express or Imputed are made a t to the utilities or effectiveness ol the methods, processes, products or procedures described or recommended herein. 0 ALCOA Engineering Standard EXCESS AIR FLOW SAFETY VALVES Mechanical 16.4.1 1988 APRIL PAGE 1 1. SCOPE This Standard covers the use, selection and location of excess air flow safety valves, intended to shut off air flow upon failure of a hose or fitting carrying compressed air. 2. GENERAL Note that: 1) Serious personal injury can result from compressed air hoses whipping, as might be caused by rupture, accidental cutting, or being suddenly disconnected. 2) Federal Regulations require that compressed air hose greater than 1/2 inch I.D., be fitted with a safety device at the source of supply or branch line to reduce pressure in the event of hose failure. This includes placement at air line take offs used with air-operated hand tools and portable hoses, but not necessarily every column air drop or outlet and excludes lines piped directly to stationary equipment. Reference Figure 1, below, which shows a typical valve in cross section, noting that: 1) During normal operation, the poppet is held in position by the retaining ring and spring pressure, as shown in "A". 2) Upon rupture or other failure, the surge of air causes the poppet to close, as shown in "B". 3) The poppet will remain closed so long as upstream pressure exceeds downstream pressure. 4) A small amount of air bleeds through the closed valve, to equalize pressure during repairs and facilitate the valve opening automatically: P*m J used on to h tll ol others then Aluminum comptny or Its subsidiaries, II t h ill noi to reproduced or copied, In whole or In ThU ilandard It th t proptrlv ol Aluminum Company ol A m tflc t tn d must without permission. b relumed on FIGURE 1 3. SELECTION Reference Appendix, Table 1, for a partial listing of acceptable valve manufacturers, valve sizes and ratings, noting that these are not intended as recommendations. Note that: 1) Flow rates in an air hose depend on compressor output (volume and pressure), line and hose diameter and length, pressure drop through the fittings and capacity of the pneumatic power tool. 2) Shut-off flow rates for valves vary with manufacturer. SUPERSEDES 1985 APRIL 4683461525 El ALCOA Engineering Standard EXCESS AIR FLOW SAFETY VALVES 0 Mechanical 16.4.1 1988 APRIL PAGE 2 Sfle o Proper valve functioning depends on selecting a valve with a shut-off flow rate somewhat higher thaui the normal flow rate for the system. o Check flow rate using a flow meter or using the following procedure: 1) Install an excess air flow safety valve based on estimated required flow, and 2) Install the highest capacity air tool to be used on the line. 3) Turn on the air supply and assure that the tool works properly. excess flow rate valve with a higher shut-off flow rate. If not, install am 4) Substitute a high capacity shut-off valve for the air tool. 5) Grasp the closed shut-off valve and open it fully. The safety valve must close. If not, an excess flow rate valve with a lower closing:flow rate must be used. ROTE: Installation of a safety flow valve without verification of its suitatbility for the system may not comply with the intent of OSHA regulations. .4 LOCATION o Locate safety valves as shown in Figure 2, below, noting that in the middle figure: 1) A valve is required at the upstream end of each branch, as well am at the source. 2) A valve at only the line source may not be sensitive enough to halt flow if a rupture occurs in a smaller bramch, since it must have capacity to feed both branches. 3) A valve is required at the source of a line feeding the branches, to prevent whipping should a rupture occur upstream from the "Y". is ill 1*1 = = t|s III 3' e-- ~'&ri2 I Figure 2. Location of valves in typical air lines. 5. REFERENCES o 29 Code of Federal Regulations, Part 1926, Section 1926.302, Paragraph 7 - "Power- Operated Hand Tools". 4683461526 y y- l < *\ This lU n d trd I t th t properly of Aluminum Company of America and must be relumed on request. It shall not be reproduced or copied, In whole or In pan, or used on behalf of others than Aluminum company or Its subsidiaries, without permission. This engineering atandanl Is provided solehr for the purpose Of disclosing Ateoa'a approach end Is notlntended to be moommendatton for tny recipient othor than Alcoa. No warranties, guarantees or representations, atpress or Imptlled a rt made as to the utilities or effectiveness of the methods, processes, products or procedural described or recommended herein. Q ALCOA Engineering Standard EXCESS AIR FLOW SAFETY VALVES r^ Mechanical 16.4.1 1988 APRIL PAGE 3 6. APPENDIX TABLE 1 EXCESS AIR FLOW SAFETY VALVES1 Manufacturer Valve Size (NPT) Approximate Shut-Off Flow at 100 psig Inlet Pressure* SCFM Hansen 4050 W. 150 St. Cleveland, Ohio 44135 Le-Hi Valve and Coupling Parker-Hannifin 30240 Lakeland Wickliffe. Ohio 44092 Perfecting Service Div. G. W. Murphy Industries P. O. Box 1949 Charlotte, N. C. 28201 Rego 4201 W. Peterson Ave. Chicago, 111. 60646 Snap-tite Union City, Pa. 16438 Thomas C. Wilson, Inc. 21-11 44th Avenue Long Island City, N.Y. 11101 1/4 3/8 1/2 3/4 1 1-1/2 2 3/4 1 1/4 3/8 1/2 3/4 1 1-1/4 1-1/2 2 3 3/8 1/2 3/4 1 1-1/2 2 3 4 1/2 3/4 1 1-1/2 2 1/4 3/8 1/2 3/4 1 1-1/4 1-1/2 2 20 SO 80 130 210 450 850 130 210 26 58 92 180 300 470 710 1050 2700 51 85 130 200 350 300 400 600 272 420 693 453 721 1268 906 1690 3171 3150 up to 701 up to 100 up to 150 up to 300 up to 700 15 42 68 84 120 140 190 260 470 680 840 1 This is a partial list. These manufacturers are not recommended over others not 2 listed. For shut-off flow rates at other Inlet pressures. P. Shut-Off Flow = (SCFM at 100 psig) /P + 14.7 V 104.7 3 f 8 85 to 130 psl working pressure. 4683461527