The Equipment Design Process
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1. Avoiding dead ends and stagnant areas
2. Using welds instead of rivets
3. Providing adequate drainage where needed
4. Selecting an appropriate flow velocity
5. Selecting an appropriate metal thickness
6. Eliminating shielded areas
7. Reducing mechanical stresses
8. Avoiding uneven heat distribution
9. Avoiding sharp turns and elbows
10. Providing adequate insulation
11. Choosing a proper shape and geometry for the system
12. Providing easy access to the structure for periodic inspection, maintenance, and replacement of damaged parts
13. Eliminating grounding of electrical circuits to the system (Many
plumbing codes for water systems are outdated and allow undesirable situations to exist. Such codes may even create problems, for
example, by requiring lead joints in some piping. Where such problems exist, it may be helpful for the utility to work with the responsible government agency to modify outdated codes.)
11.3.5 gas industry
11.3.5.1 Types of Corrosion in Underground Piping
The problems of corrosion will be confined to the piping system, mainly
underground. If the system contains restrained lines in an above-ground
system that is subject to dust or sand movement, then the treatment of the
piping will follow the underground system.
Corrosion in other parts of the system, such as the compressors and processing equipment, is discussed in other industrial sections such as Section
11.3.3.2. Corrosion in compressor station equipment is handled by water
treatment and inhibition of the cooling waters and is not of major concern
to corrosion experts in the gas industry. Processing vessels are handled
similarly to the equipment covered in the petroleum industry by the use of
inhibitors. Corrosion coupons and equipment inspection are used to monitor
corrosion rates in the equipment.
The prevalent corrosion problems of underground piping systems are galvanic and differential concentration cells common to ferrous metals in soils
and natural waters with resultant pitting-type corrosion. A serious problem
can result in certain areas from stray DC current interference from nearby
coal mines, street railways, and industrial use of Earth-grounded DC power.
Bacterial or microbiological corrosion is generally thought to be a serious
371
1. Avoiding dead ends and stagnant areas
2. Using welds instead of rivets
3. Providing adequate drainage where needed
4. Selecting an appropriate flow velocity
5. Selecting an appropriate metal thickness
6. Eliminating shielded areas
7. Reducing mechanical stresses
8. Avoiding uneven heat distribution
9. Avoiding sharp turns and elbows
10. Providing adequate insulation
11. Choosing a proper shape and geometry for the system
12. Providing easy access to the structure for periodic inspection, maintenance, and replacement of damaged parts
13. Eliminating grounding of electrical circuits to the system (Many
plumbing codes for water systems are outdated and allow undesirable situations to exist. Such codes may even create problems, for
example, by requiring lead joints in some piping. Where such problems exist, it may be helpful for the utility to work with the responsible government agency to modify outdated codes.)
11.3.5 gas industry
11.3.5.1 Types of Corrosion in Underground Piping
The problems of corrosion will be confined to the piping system, mainly
underground. If the system contains restrained lines in an above-ground
system that is subject to dust or sand movement, then the treatment of the
piping will follow the underground system.
Corrosion in other parts of the system, such as the compressors and processing equipment, is discussed in other industrial sections such as Section
11.3.3.2. Corrosion in compressor station equipment is handled by water
treatment and inhibition of the cooling waters and is not of major concern
to corrosion experts in the gas industry. Processing vessels are handled
similarly to the equipment covered in the petroleum industry by the use of
inhibitors. Corrosion coupons and equipment inspection are used to monitor
corrosion rates in the equipment.
The prevalent corrosion problems of underground piping systems are galvanic and differential concentration cells common to ferrous metals in soils
and natural waters with resultant pitting-type corrosion. A serious problem
can result in certain areas from stray DC current interference from nearby
coal mines, street railways, and industrial use of Earth-grounded DC power.
Bacterial or microbiological corrosion is generally thought to be a serious