The importance and role of air valves in a force main

1. BURP PROUDLY:
The Importance of Air Valves
Brian Gongol
DJ Gongol & Associates, Inc.
March 30, 2016
Iowa WEA Region 5 Conference
Huxley, Iowa

2. Let's start with a beer keg

3. If you pump a few times, you add pressure

4. Pumping too much creates foamy beer

5. Beer is relatively incompressible

6. Releasing a little volume eases lots of pressure

7. Water in a pressurized system: Same behavior

8. Not zero like a solid (steel or concrete)

9. But close

10. Squirt guns and belly flops prove it

11. Everyone knows two ways you can get gas

12. 1. Swallowing too much air

13. 2. Eating something that generates gas

14. There are two ways to get rid of it

15. Having gas in your system is unpleasant

16. Gas stretches your elastic innards

17. Wastewater systems do not have the same elasticity

18. When gas collects, it doesn't have anywhere to go

19. But gas inside a force main is just as real
as the gas you get from eating a burrito

20. Force mains are not elastic

21. Pressure inside does two things

22. 1. Displaces water that should be flowing through

23. 2. Places pressure on pipes that can cause damage

24. This is why we use air-release valves

25. [ ENTER: THE WIRE HANGER ]

26. But unlike your digestive tract, hard pipes have to stay full of
something at all times

27. In addition to releasing air, we have to break vacuums as well

28. Four different types of valves need to be considered

29. 1. Air-release

30. [ AIR-RELEASE VIDEO ]

31. 2. Vacuum-breaker

32. [ VACUUM-BREAKER VIDEO ]

33. 3. Air-vac

34. 4. Combination air valves

35. [ COMBINATION AIR VALVE VIDEO ]

36. Where these are located

37. Typically some kind of air release at the pump site

38. Needed for priming

39. Frequently a site of air capture

40. Air-release at the highest point is not enough

41. Air release is needed at all local high points

42. Also recommended on long stretches of pipe rise

43. Vacuum-breakers typically needed at the same points

44. Weight of a column of water
 4" diameter, 500' long
 43.55 cubic feet
 325.75 gallons

45. At 8.3 lbs per gallon: 2700 lbs. (a Honda Civic)

46. For big exhaust, air-vac valves may be enough

47. But if mains needs to "burp", get combination valves

48. Sizing is a little bit of black magic, but not too much

49. When in doubt, go big

50. Filling a pipeline/force main

51. Filling a pipeline/force main

52. Filling a pipeline/force main

53. Filling a pipeline/force main

54. Filling a pipeline/force main

55. Filling a pipeline/force main

56. Filling a pipeline/force main

57. Filling a pipeline/force main

58. Filling a pipeline/force main

59. Filling a pipeline/force main

60. Filling a pipeline/force main

61. Filling a pipeline/force main

62. Filling a pipeline/force main

63. Breaking a vacuum

64. Breaking a vacuum

65. Breaking a vacuum

66. Breaking a vacuum - refilling

67. Air valves are not shock absorbers, too

68. Water is not like air in a storm door cushion

69. But also unlike pushing on a pool cue

70. Energy is transmitted quickly but not instantly

71. Energy is conducted as a wave

72. Air valves and surge valves are complementary

73. Air is vastly more compressible than water

74. Water needs surge control to protect pipes

75. Surge is like a train starting or stopping

76. Energy transmits through couplers

77. Surge in a filled force main

78. Surge in a filled force main

79. Surge in a filled force main

80. Surge in a filled force main

81. Surge in a filled force main

82. Surge in a filled force main

83. Surge in a filled force main

84. Surge in a filled force main

85. Surge in a filled force main

86. Surge in a filled force main

87. Surge in a filled force main

88. Surge in a filled force main

89. Surge in a filled force main

90. Surge in a filled force main

91. Surge in a filled force main

92. Surge in a filled force main

93. Surge in a filled force main

94. Surge in a filled force main

95. Surge in a filled force main

96. Surge in a filled force main

97. Surge in a filled force main

98. Surge in a filled force main

99. Surge in a filled force main

100. Surge in a filled force main

101. Surge in a filled force main

102. Surge in a filled force main

103. Don't make a bad situation worse

104. Low point main break - with vac breakers

105. Low point main break - with vac breakers

106. Low point main break - with vac breakers

107. Low point main break - with vac breakers

108. Low point main break - with vac breakers

109. Low point main break - with vac breakers

110. Low point main break without vac breakers

111. Low point main break without vac breakers

112. Low point main break without vac breakers

113. Low point main break without vac breakers

114. Low point main break without vac breakers

115. Low point main break without vac breakers

116. Low point main break without vac breakers

117. Low point main break without vac breakers

118. Low point main break without vac breakers

119. All the sizing in the world is useless if you don't maintain

120. Backflushing

121. [ BACKFLUSHING VIDEO ]

122. Risks damaging parts

123. May not remove buildup

124. Could just temporarily move the clog

125. Alternative: Wiping and scrubbing

126. [ CLEANING VIDEO ]

127. Isolation is important

128. Knife gate valves for isolation

129. Plug valves for isolation

130. Valves aren't just an accessory or a "want"

131. Proper valving is essential to the proper operation of a force main

132. Slam is the train sliding back downhill

133. Vacuum-breaking upon pressure drop

134. Air in solution in water: About 2%

135. Air restricts pipe diameter

136. Can be significant

137. Air pockets will build

138. Imagine trapping a tough balloon in the pipe

139. Lots of compression possible...

140. ...but dangerous high pressure results

141. Upsurge and downsurge are hydraulic

142. Slam is mechanical

143. Slam comes from column reversal

144. Slam and surge are independent

145. Check valves are used for protection

146. Prevent simple column reversal

147. Ball check valves

148. Weighted-flapper check valves

149. Cushioned check valves

150. Non-slam check valves

151. Close fast enough to prevent slam

152. Example: Sudden power loss

153. Example: Sudden power loss

154. Example: Sudden power loss

155. Example: Sudden power loss

156. Don't close too fast for pumps and systems

157. Quick self-closure isn't actual slam

158. Slam is involuntary seating of the valve

159. Some valves can control both surge and slam
 Checktronic
 Overcoming high head after bringing pump up to speed

160. Surge control valve

161. Water air-release valve

162. Sewage air-release valve

163. Wide-body air-release valve

164. To recap
 Force mains need to burp
 Force mains need to pass gas
 Force mains need to swallow air
 Air absorbs some wave energy, but not all
 Air pressure, vacuums, and surge waves can damage pipes
 Well-maintained automatic valves are an important feature

165. You don't have to figure it out alone
 Free surge analysis available
 Air-release analysis also available
 Call: 515-223-4144
 Email: info@djgongol.com

166. Questions?
 Thank you for coming!

167. Thank you for your attention!
 Contact us anytime with
questions
 Brian Gongol
 DJ Gongol & Associates
 515-223-4144
 info@djgongol.com

168. References
 Catalog photos of valves are courtesy GA Industries
 All other photos are original work by Brian Gongol. All rights
reserved.