3.1.1
Piping
3.1.1.1
Pre-Installation Cleaning
Disassemble positive pressure pipe, fittings, valves, and other components.
Provide only pipe and fittings which have been thoroughly washed. Use the
following cleaning procedures:
a.
Mix the solution of sodium carbonate or trisodium phosphate in the
proportion of 454 gram one pound dry chemical in 11.40 liters 3
gallons of water.
b.
Maintain the resulting solution at minimum 82 degrees C 180
degrees F.
c.
Wash thoroughly, scrubbing as required. Rinse with clean water
and blow dry with oil-free dry nitrogen.
Effectively cap ends of the pipe, fittings or valves, and label "CAUTION!
CLEANED FOR MEDICAL GAS SERVICE." In lieu of cleaning by the installer at
the job site, each pipe, fitting and valve may be supplied "CLEAN FOR
OXYGEN SERVICE" by the manufacturer. Do not use carbon tetrachloride,
hydrocarbon, or halogenated hydrocarbon solvents.
3.1.1.2
Piping Installation
Exercise care with cutting, brushing, and reaming tools and equipment to
prevent oil, grease, and dirt from entering pipe and components. Rewash
contaminated pipe and components. Cut pipe square and accurately to
measurements and work into place without springing or forcing. Follow the
general arrangement indicated. At the end of each work shift shut off
valves, and cap or plug open ends. As work progresses, valve off each
section to prevent moisture or dirt from entering piping.
3.1.1.3
Hangers and Supports Installation
Install hangers and supports in accordance with MSS SP-69 and MSS SP-89
except that spacing of the hangers and supports shall be in accordance with
Table 2.
TABLE 2
MAXIMUM SPAN FOR PIPE HANGERS (mm)
Copper tube, Type K (Cu-K) and Type L (Cu-L); PVC Schedule 40 and 80 (PVC);
brass and stainless steel (SS)
Pipe Size
Cu-K and Brass
Cu-L
PVC
SS
(mm)
15
1140
1060
1060
1520
20
1290
1290
1060
1750
25
1520
1440
1210
1980
40
1750
1670
1370
2280
50
1980
1980
1370
2590
65
2210
2130
---
2810
80
2360
2280
1670
3120
90
2510
2510
---
3350
SECTION 15217N
Page 25
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