SURGE ANALYSIS OF PUMPING SYSTEMS omas row ey, eston nge , Stew St ewar artt Nol Nolan and, d, PE – Cr Cris istt En Engi gine neer ers s Scott Fos Foster ter,, PE – Flow Science Science October 14, 2014
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a ro o
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water Water Little Rock, AR – SUA Stillw Stillwate aterr, OK –
• Recommendations
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water Water Little Rock, AR – SUA Stillw Stillwate aterr, OK –
• Recommendations
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water – Stillwater, OK –
• Recommendations
• – Pump Startup – – Power Loss –
v
u
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• Secondary Surge Transients – Air Valve – Water Column Separation
• – Pump Startup – – Power Loss –
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• Secondary Surge Transients – Air Valve – Water Column Separation
• – Pump Startup – – Power Loss –
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• Secondary Surge Transients – Air Valve
• – Pump Startup – – Power Loss –
v
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• Secondary Surge Transients – Air Valve – Water Column Separation
• – Pump Startup – – Power Loss –
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• Secondary Surge Transients – Air Valve – Water Column Separation
• – Pump Startup – – Power Loss –
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• Secondary Surge Transients – Air Valve – Water Column Separation @ High Spots
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water – Stillwater, OK –
• Recommendations
Factors Influencing Surge orma on • – Pipeline profile (particularly high points) – Pipeline and lining Material – Configuration (Storage locations)
• Pipe Appurtenances – – Valve Types and opening/Closing – Type of Check Valves
•
ump ea ures – Pump performance curves and operating speeds – Rotational moment of inertia’s for assemblies
um /motor
• Pipeline velocities must be low to reduce the • Surges only occur in long pipelines • The noise and knock in a s stem is an indicator of the magnitude of a surge • Surge protection devices should be installed on an
accurately determine the magnitude of surges • The use of sur e rotection devices are not economically viable • Pressures in a system must be high before r u ur ur
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water – Stillwater, OK –
• Recommendations
How can you determine if Surge is an ssue • Ban in
Noises and Vibration
– Pressure waves bouncing from piping – Check valve slamming
requen p pe rea s n e ame places especially near pump station or low hi h oints in the s stem. • System Measurements (transients occur too quickly for normal PT’s) • Difficult to observe due to infrequent occurrence and difficulty in monitoring. •
Why Should You Care About Water ammer. • • Pipe Materials Behave Differently: – Plastic: Lower ro a ation but more susceptible to fatigue from cyclic loading. – Steel, Concrete: Higher pressure rise but .
• Contamination Potential
(Gauges, Flowmeters, etc.)
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water – Stillwater, OK –
• Recommendations
Types of Surge Suppression qu pmen - ass ve •
Types of Surge Suppression qu pmen - ass ve •
Types of Surge Suppression qu pmen - ass ve • Controlled Pum
Startu /Shutdown
– Provide wirth “S-curve feature” to Time with Valves – Not all Soft Starts Created Equal – Volta e/Tor ue Control More Im ortant than Current.
Types of Surge Suppression qu pmen • – Pump Curve – – Anti Reverse - Ratchet
Types of Surge Suppression qu pmen - c ve •
Location)
Types of Surge Suppression qu pmen - c ve •
Location)
Types of Surge Suppression ev ces - c ve • • Surge Tanks – a
er – Hydropneumatic – Surge Towers
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water – Stillwater, OK –
• Recommendations
CAW Maumelle Pump Station s ory 600 550 500 ) t ( n o i t a v e l
E
450 400 350
250 200
Breaks on Breaks 72 ‐inchon
‐
Distance (miles) Pipeline Elevation Pipeline Pressure
Protect, Replace or Bypass Area of Highest Pressures
ARV
48”
30”
60”
” 30 mgd 48”
30”
60 ”
12” 30 mgd 36”
24”
12” 48”
30 mgd 36”
24”
”
60” 12” 30 mgd
ARV
24”
”
Pumps 1‐4
48” 36”
ARV
15 mgd
14”
48”
24”
E
30 mgd
48”
Pumps 5‐7
72” Fi ure 1 –Existin Schematic Maumelle Pum Station Lake Maumelle Pump Station and Transmission Main Preliminary Design Technical Memorandum Central Arkansas Water
• All Air/Vacuum Relief Valves equipped with controlled ventin slow closin . • All seven pumps are operating (174 mgd at 333-341 TDH) • One of the river crossings is out of service (highest ve ocity • Pump Control Valves Close within 60 seconds of power loss. ve urge n c pa or a ves s u y open • following activation (Pressure below 75 psig). • SAV’s Remain in operation for 30 seconds and close . • Both the 72-inch and 48-inch Transmission Mains are hydraulically connected.
At all times Max HGL < 1.33 x Pressure Rating
Proper Operation of CAV’s Crucial to protection scheme. Areas of High Potential for Vapor Cavity Formation and Collapse
Fi ure 2 –Existin S stem Lake Maumelle Transmission Mains Lake Maumelle Pump Station and Transmission Main Preliminary Design Technical Memorandum Central Arkansas Water
At all times Max HGL < 1.33 x Pressure Rating
CAV’s inadequate to prevent vapor cavity formation Areas of High Potential for Vapor Cavity Formation and Collapse
Repressurization VC collapse
Potential cycling of event very damaging to PCCP.
Rapid Drop of Pressure at PS
Fi ure 2 –Existin S stem Lake Maumelle Transmission Mains Lake Maumelle Pump Station and Transmission Main Preliminary Design Technical Memorandum Central Arkansas Water
• Install Three 12 ft diameter x 60 ft lon surge tanks with 45% air. • Install tanks at pump station. • Insta new va ves to c ose wit in seconds of power failure at pump • Retain existing SAV’s for increased level of protection. • Install Surge Checks on CAV’s at stations further down the pipes.
CAV ‘s require controlled venting
CAV ‘s require
ARV
48”
Dual Disc Check Valve – Lug Type
30”
60”
48”
VFD 12” Dismantling Joint
30 mgd
DMJ
30”
60” ARV
VFD D
24”
12”
J
30 mgd 36”
ARV
15 mgd
24”
12”
48”
14”
ARV
15 mgd
24”
48”
30 mgd
36”
24”
60”
24” 12”
VFD
30 mgd
30 30 mgd J D M J D
36” 30”
” J D M
48” H
30” 48”
”
”
Air Compressor (Typ of 4)
”
Fi ure 5–Pro osed Schematic Sur e Tanks O tion 1 Lake Maumelle Pump Station and Transmission Main Preliminary Design Technical Memorandum Central Arkansas Water
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water – Stillwater, OK –
• Recommendations
M
36”
E x i s t i n g K w R a w W a t e r P i p e l i n e S c h e m a t i c
42” 48”
20”
Kaw Reservoir
36”
36”
36”
36”
9 mgd, 173 psig VT Pump 1,000 HP (typ of 2)
Large Pumps
Legend
24” M
Flowmeter
F M
M
Strainer M
Electric Actuated Control Valve Globe Style Check Valve
4 mgd, 78 psig VT Pump 200 HP (typ of 3)
M
Constant Speed Pump
ma V
36”
umps
Variable Speed Pump 24”
4MG Raw Water Storage Tank
Butterfly Isolation Valve
To Stillwater WTP
F I G U R E 1 .1
M
FM
”
24”
24” 12”
From Stillwater WTP
Draft Report August 2012
24” 36”
To OSU WTP
42”
E x i s t i n g K a w R a w W a t e r P i p e l i n e P r o f i l e
F I G U R E 2 . 3
2‐inch combination Air Valve (typ) Sta. 633+48 Man way Sta. 1931+68 (Tank Farm)
Sta. 1307+92 Man way
Horizontal Scale: 0.5 inch = 2 miles
Draft Report August 2012
•
were occurring due to: – – Lack of Proper Air/Vacuum Relief Valves
Sta. 633+ 48 4‐inch CAV
R e c o m e n d e d L o c a t i o n s f o r A V ’ s
Sta. 525+ 00 4‐inch CAV
Sta. 117+ 43
‐
Sta. 1307+92 4‐inch CAV
Horizontal Scale: 0.5 inch = 2 miles Sta. 1677+51 2‐inch CAV (relocated)
F I G U R E 4 .1
Sta. 756+05 2‐inch CAV (relocated)
Sta. 368+75 2‐inch CAV (relocated) Sta. 00+00 2‐inch CAV (relocated) Sta. 190+29 2‐inch CAV (relocated)
Final Report October 20122
• Factors Causin • • • •
Sur e in Pum in S stems Factors Influencing Surge Severity Why Should I Care about Surge? Types of Surge Suppression Systems Case Studies: a oma y, – Central Arkansas Water – Stillwater, OK –
• Recommendations
Conclusions and ecommen a ons =
•
Surge • Alwa s erform a sur e h draulic analysis: – On new systems – On existing systems to change conditions – To determine timing of pump/valve startup.
•
ys em con
ons w
– Active or Passive –
c a e so u on:
