Ball Valves - exakm.gr

Ball Valves

ERHARD Ball Valves for Water and Waste Water
- Perfected and optimized type thanks to 30 years experience
➬ Body: two-part casting, inlet and
outlet part
➬ Spherical design for maximum
pressure ratings
➬ Streamlined shape
➬ Many patterns available
➬ Obturator: ball designed as simple
and solid casting
➬ With adjustable profile ring fixed
to the ball
➬ Offset ball: ball sealing lifts from
the body seat after a movement of
only 3 degrees
Principle of Design:
Closed
position
Body inlet
Body seat
Body
outlet
➬ Flow guided around the ball in
intermediate positions - stable,
dynamic characteristics
➬ Offset ball produces a closing tendency
over the closing range
➬ Low wear and tear irrespective of
deposits/foreign bodies
➬ Full, unreduced bore
➬ Solid body seat of stainless steel
Ball
Profile ring
➬ Positive connection of shaft and
ball by means of keys
Drive shaft
➬ Variable, modular choice of
operating gears and actuators
➬ High-grade surface protection
EKB epoxy coating
Bearing bushes
Key connection
The ERHARD Ball Valve begins where other valves give up:
Ball Valves are suitable
for varied applications in the
range of water and waste water
engineering - complementary to
gate valves and butterfly valves -
especially in case of
➬ high flow velocities
(up to max. 15 m/s)
➬ high pressure ratings
(up to PN 160)
➬ energy saving and
economical operation
Pressure rating PN [bars]
100
63
40
25
16
10
6
Butterfly
Valve*)
Gate
Valve
Ball Valve
to EN 1074-2
Special cases,
upon request
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Flow velocity v [m/s]

ERHARD Ball Valves
Convincing advantages
➬ Extremely low head-loss
coefficient in open position,
thus very low head loss
➬ In open position, the profile
ring is protected - off the
flow
Upon request, the ball valve is
available with the following
optional features:
➬ Available for highest
pressures
➬ The fact that the flow is
guided around the ball
ensures stable characteristics
and flushing effect in gap
areas
➬ Robust sealing zone insensitive
to deposits - in contrast to
the known ball valve designs
with hydraulically actuated
sealing
➬ Sealing on both sides
➬ Modular principle:
➬ Repair orifice (for exchangeing
the main seal in open
position of the valve)
➬ Repair seal (additional main
seal integrated on the inlet
side)
➬ 3-way Ball Valve
Save energy - it’s YOUR money that is at stake
Thanks to its streamlined and
unreduced shape, the ERHARD
Ball Valve offers considerable
advantages in terms of pressure
and flow-rate losses, even within
the range of low and medium
pressure ratings.
For example, 90 % of the energy
costs in water works are used
exclusively for pumping operation.
Optimum use and conversion
of these energy costs
have become increasingly
important. Optimized combination
of pump and valve or - in
case of hydroelectric plants -
valve and turbine, offers big
energy saving potentials which
can easily be expressed in terms
of money.
Energy saving potentials for different valve types
Example: Pump starting valve
Energy saving potentials for different valve types
Example: Pump starting valve
Efficiency: 0.75
Operating time:
8760 h
Annual saving in thousand DM
Flow velocity:
5 m/s
K value Needle Valve: 1.4
K value Ball Valve: 0.05
K value Butterfly Valve: 0.4
Price of electricity: 0.1 DM /kWh
Ball valve compared
with Needle Valve
Ball Valve compared
with Butterfly Valve
M
Pump
v
Starting
valve
Nominal diameter DN
For energy saving, the following equation is applicable:
π 1
∆W electr. = ––––– · – · DN 2 · t · ρ · (K 2 - K 1 ) · v 3
8000 η
Symbols and units:
∆W electrical energy-loss difference [kWh]
η overall efficiency (pump and motor) -
DN pipeline/valve nominal dia [m]
t operating time of valve [h]
ρ density of the flow medium [kg/m 3 ]
K 2 head-loss coefficient of the valve to be compared -
K 1 head-loss coefficient of the Ball Valve -
v flow velocity of the medium [m/s]
The example based on assumed data shows
that considerable energy can be saved with
increasing size DN.
Thus, e.g. for DN 800 the annual energy
saving can be compared as follows:
➬ Ball Valve instead of Needle Valve: about
DM 50,000.-
➬ Ball Valve instead of Butterfly Valve:
about DM 13,000.-
In any case, a comparative calculation is
always worth it. In practice, the period of
amortization is about 3 to 5 years without
considering the other advantages of the Ball
Valve.

ERHARD Ball Valves for Water and Waste Water
Typical Examples of Applications
➬ Isolating Valve for high pressures
and flow velocities
➬ Drain and/or Washout Valve
➬ Safety/emergency isolating
valve in bottom outlets or
hydroelectric power plants
➬ Economical inlet/starting valve
upstream of turbines/downstream
of pumps
➬ Main burst safety valve in
water supply and hydroelectric
plants
➬ Universal isolating valve for
water supply and for sewage
and waste-water engineering
with convincing features
(flushing effect, swabbing of
pipeline possible, etc.)
➬ and many others - references
available.
Scope of Supply/Service
➬ Sizes
DN 80 -1200
➬ Pressure ratings
PN 10 -160
➬ Range of temperatures
up to +130 °C
Operating gears and actuators
For operating the Ball Valves,
the approved Line of ERHARD
Operating Gears and Actuators is
available as follows:
Design/Dimensioning
The following data are necessary
for choosing a Ball Valve or preparing
a quotation:
➬ Size DN
➬ Pressure rating PN
Materials
➬ Body/ball
depending on pressure rating:
cast iron
GG-25
ductile cast iron
GGG-50
GGG-40.3
cast steel
GS-C25N
GS-24Mn5
➬ Profile ring/elastomers
(depending on flow medium
and PN): NBR, EPDM,
PTFE/carbon, PUR
➬ Travelling-nut/slider crank
gearbox, directly or remoteoperated,
manual or electric
➬ Pneumatic and hydraulic
actuators
➬ Application: Isolating, washout/drain,
safety device, main
burst safety valve ....
➬ Operating conditions:
flow velocities/flow rates,
pressure conditions
(static/dynamic)
➬ Seat, shafts, wetted bolts:
stainless steel
➬ Bearing bushes:
bronze, maintenance-free
➬ Special materials according to
flow medium and customers’
specification
Surface protection systems
➬ EKB epoxy coating or
according to customers’
specification
➬ Special actuators as e.g.
weight-loaded hydraulic
actuator (see separate leaflet)
➬ Flow medium (water/waste
water), analysis if available
➬ Operating gear or actuator
➬ Situation of installation (space
requirement, configuration,
etc.)
➬ Other specifications
ERHARD Ball Valve
➬ Competent advice, supply, and service from the valve and actuator
to measuring and control engineering.
➬ Please, contact us! We will be glad to help you.
Postfach 1280 · D-89502 Heidenheim
Phone: (07321) 320-0 · Fax: (07321) 320-525
http://www.erhard.de
e-mail: export@erhard.de
Data corresponding to the latest level of development. Modifications reserved. Printed in the Federal Republic of Germany. WH 10/99