Infiltration-inflow sewer line analyzer

• US 4,211,111 A
• Filed: 05/12/1978
• Issued: 07/08/1980
• Est. Priority Date: 06/30/1977
• Status: Expired due to Term

• Current Assignee: Peter D. Petroff
• Original Assignee: Peter D. Petroff
• Inventors: Petroff, Peter D.
• Primary Examiner(s): Woodiel, Donald O.
• Application Number:
  US05/905,196
• Time in Patent Office: 788 Days
• Field of Search: 73/299, 73/215, 73/290 R, 73/194 R, 73/212, 73/420, 73/215, 73/302, 73/439, 73/40.5
• US Class Current: 73/195
• CPC Class Codes: G01M 3/2815 using pressure measurements

Abstract

A method and means of determining inflow (undesired pipe drains to a sewer) and infiltration (sewer pipe leakage) into sewer lines by a coordinate measurement of pressure in sewer pipes at several locations, particularly measuring flow during rainfall and for a discrete period thereafter and comparing the results with dry periods.

Claims

1. The method of identification of, and measurement of magnitude and location of, inflow and infiltration into a first sewer pipe line having an entrance end connected to, and receiving flow from, a first manhole, and said first sewer pipe line having an exit end connected to a second manhole, and wherein there is a second sewer pipe line having an exit pipe line supplying flow to said first manhole comprising:

(A) making a first series of time identified measurements of the magnitude of flow out of said second pipe line into said first manhole for a series of discrete times during an average dry, no rainfall, period of a day;

(B) making a like time related series of flow measurements out of said second pipe line for a like period of a day during which rainfall occurs, including measurements from the time that a rainfall commences and extending for a period beyond the end of the rainfall;

(C) subtracting like timed measurements obtained with respect to paragraph (A) from those obtained with respect to paragraph (B);

(D) making a like timed and time identified series of magnitude of flow measurement out of said first pipe line into said second manhole for an average dry day;

(E) making a like timed and time identified series of magnitude of flow measurements out of said first pipe line into said second manhole for the period of measurement defined in paragraph (B);

(F) subtracting like timed measurements obtained in paragraph (D) from those obtained from measurements of paragraph (E) for (1) a period during said rainfall, and (2) a selected period following a rainfall;

(G) subtracting like timed quantities obtained with respect to computations made in paragraph (C) from those obtained in accordance with paragraph (F), whereby differences for a rain period are representative of "inflow" into said first sewer pipe line, and differences for the period following a rain are measurements of "infiltration" into said first pipe line; and

(H) said flow measurements comprise a measurement of liquid heights within the exit end region of each said pipe line at a point from the exit end of that pipe line equal to at least the interior diameter of a said pipe line, and the region between the point of measurement and exit end of the pipe line in which said height is being measured is unobstructed by a weir.

2. The method of measurement as set forth in claim 1 wherein liquid height measurements include the measurement of liquid pressure adjacent the bottom of said pipe line.