8224

• UCREFRP Catalog Number: 8224
• Author: Lapham, W. W., F. D. Wilde and M. T. Koterba.
• Title: Ground-Water Data-Collection Protocols and Procedures for hte National Water-Quality Assessment Progra
• USFW Year: 1995.
• USFW - Doc Type: Selection, Installation, and Documentation of Wells, and collection of Related Data.
• Copyright Material: NO

Table 6. Some general characteristics of materials used for well casing and screens (modified
from T.E. Imbrigiotta, U.S. Geological Survey, written commun., 1989)--Continued
[PTFE, polytetrafluoroethylene; PVC, polyvinylchloride; SS, stainless steel]
STAINLESS STEELa
- Generally has high corrosion resistance, but varies with type.
- Corrosion can occur under acidic and oxidizing conditions.
- Corrosion products are mostly iron compounds, with some trace elements (see below).
- Primarily two common types:
(1) Stainless steel 304 (SS304): Iron alloyed with the following elements (percentages
approximate): chromium (18-20 percent), nickel (8-11 percent), manganese (2 per-
cent), silicon (0.75 percent), carbon (0.08 percent), phosphorus (0.4 percent), sulfur
(0.03 percent).
(2) Stainless steel 316 (SS316): Iron alloyed with the following elements (percentages
approximate): chromium (16-18 percent), nickel (10-14 percent), manganese (2 per-
cent), molybdenum (2-3 percent), silicon (1 percent), carbon (0.08 percent),
phosphorus (0.4 percent), sulfur (0.03 percent).
- Corrosion resistance is good for SS304 and excellent for SS316.
- Expensive.
GALVANIZED STEELa
- Less corrosion resistance than SS304 or SS316 and more resistance to corrosion than
carbon steel (below).
- Oxide coating could dissolve under chemically reduced conditions releasing zinc and
cadmium.
- Weathered or corroded surfaces present active adsorption sites for organic and inorganic
constituents.
- Inexpensive.
CARBON STEELa
- Corrosion products (for example, iron and manganese oxides, metal sulfides, and dis-
solved metal species) can occur.
- Sorption of organic compounds onto metal corrosion products is possible.
- Weathered surfaces present active adsorption sites for organic and inorganic constituents.
- Inexpensive.
aResidues, such as threading lubricants used in production or contamination during
shipping, require that all materials be ,cleaned inside and out prior to installation.
bpossible construction alternative is to use a PTFE screen with threaded PVC casing.
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