5. Installation & Fabrication Guidelines
Q1: What are proper handling procedures?
A1: Always:
Use nylon slings or padded hooks to prevent coating damage
Store on wooden dunnage to prevent ground moisture contact
Keep different materials separated to prevent galvanic corrosion
Protect threads with plastic caps during transport
Avoid dragging pipes to prevent surface scratches
Q2: What welding methods are suitable?
A2: Common methods include:
Shielded Metal Arc Welding (SMAW) with E6010/E7018 rods
Gas Metal Arc Welding (GMAW) using ER70S-3/-6 wire
For galvanized pipe, remove zinc 1-2 inches from weld area first
Use lower heat input to minimize HAZ
Always follow qualified welding procedures
Q3: How should pipes be supported?
A3: Follow these spacing guidelines:
Every 6-8 feet for 1/2" pipe
Every 10-12 feet for 2" pipe
Every 15 feet for 6" pipe
Use:
Cushioned clamps for galvanized pipe
Insulating spacers when contacting dissimilar metals
Expansion loops in long runs
Proper hanger sizing for weight + contents
Q4: What threading practices apply?
A4: Key requirements:
Use NPT (National Pipe Taper) thread standard
Cut threads to ASME B1.20.1 specifications
Apply thread compound (except on gas lines)
Never thread galvanized pipe without re-coating
Inspect threads for proper engagement (hand-tight plus 2-3 turns)
Avoid over-tightening to prevent cracking
Q5: What are common installation mistakes?
A5: Frequent errors include:
Mixing galvanized and copper without dielectric unions
Inadequate slope for drainage (minimum 1/8" per foot)
Improper support spacing causing sagging
Failing to clean pipes before assembly
Ignoring expansion provisions in hot systems
Using excessive thread compound that can contaminate systems
