Double Eccentric Half Ball Valve is a high performance valve developed with advanced technology.It also called Semi Ball Valve,C type ball valve and E type ball valve.It is designed on the base of O type ball valve,which solves the difficulties of conveyance of “solid-liquid” and “solid-gas” two phase medium.Mainly applied : 1.Inlet and outlet of pumps for Ammonia water I and Ammonia water II beside carbonating tower 2.Inlet and outlet of mother liquor I and mother liquor II pumps . 3.Installation on the pipe under the cabonation tower to control of shut off the secondary salt solution.

1. Technical Description for Double Eccentric Half Ball Valve
一、Product Performance
Double Eccentric is designed
and developed on the basis of
normal ball valve ， the closing
parts of the valve is a semi
spherical ball which rotates 90
degree around the center line of
the valve body to achieve valve
opening and closing. The valve
belongs to the category of quarter
turn valves.The double eccentric
half ball valve is designed
according to the principle of Double Eccentric-Wedge CAM. Its closure is tightly and reliable, can
achieve zero leakage,that present a newly step of sealing performance of metal sealing double
eccentric half ball valve.
1.Design Principle
Design Principle of Double Eccentric Half Ball Valve：QBQ type double eccentric half ball valve is
designed according to the Eccentric-Wedge CAM ， self locking positioning that guarantee the
reliable sealing. There is one eccentric center E in the radial direction between the valve stem
center and the the flow channel center of the valve,and one eccentric center in the axial direction
between the sealing face center and the valve stem.（that is the rotating center of the disc),at the
same time E=e，the special of this structure is reliable and tight wedge between the valve disc and
valve seat.It also has the function of cutting off the medium or the crystalline substance.The
eccentric distance makes the valve opening and closing torque is small and easy to operate.The
change of the eccentric wheel and the wedge angle of the Eccentric-Wedge CAM is shown as
bellow:

2. Following is the eccentric position during the rotation of the double eccentric half ball valve：
2.2、 Product Features
The unique eccentric structure that makes the valve overcome the resistance during the
moment of the valve opening and closing,the during other time of the valve opening and closing
moment, the valve is in no rotation state without resistant. Also the valve only rotates 90°，it is very
easier to open and close the valve，and the torque of the diving device is shorten. The double
eccentric structure takes the CAM effect during the valve opening and closing can cut off the
crystallization that scaled on the sealing surface.so that the sealing performance is guaranteed to
be safe and reliable.
There is no dead space inner of the valve cavity.Especially after the valve opening, the valve disc
totally go into the concealed sphere cavity，there is nearly no resistance to the medium, so the
pressure lost is very small.
1、Straight through type body: it is very applicable to the solid -liquid two phase medium，when
opening the valve, the valve disc and valve seat moves away from each other(compared with ball
valve)，so there will be no blocking happens.

3. 2、Easy opening and closing：When the valve is opened about 5°, the valve disc and valve seat
moves away from each other，then there is no contact with each other, so the opening torque is small,
the valve is very east to operate.
3、When closing the valve: there is a force generated from valve disc and valve seat that can remove
the scales on the sealing surface, so the sealing is tight and reliable, the valve anti-scaling
performance is very satisfied.
4 、 When there is wear between the valve sealing parts,the double eccentric structure can
automatically make the spherical compensate for wear to guarantee the sealing performance of the
valve so that the valve working life is long and there will be no leakage after the valve is used for a
long time.
5 、 The valve is designed with metal sealing structure ， the valve disc and valve seat material is
selected with C4 steel and processed with special harden treatment, both wear resistant and
corrosion resistant is very good. So the valve is very suitable chlorine root ions, ammonia ions
and other corrosive medium in the soda industry. the soda ash industry for the medium of
6、Valve body material is selected with SS316l, valve shaft material is selected with SSF316.
7 、 Because the medium containing ammonia which has corrosion on the cooper material,so we
choose the non cooper material that is Ammonia corrosion resistant.
二、Main Technical Performance and Materials
3.1 Technical Performance
Nominal Pressure（MPa) 1.0 1.6
Strength Test Pressure（MPa) 1.5 2.4
Sealing Test Pressure（MPa) 1.1 1.76
Applicable Medium
Mother Liquor、Ammoniacal Brine、Neutralizing water etc that
has corrosion characteristics
3.2 Main Parts and Material
Part Name Material Remark
Valve Body CF3M SS316L Castings
Valve Stem F316 Forgings
Valve Disc C4 Special Hardening Treatment
Valve Seat C4 Special Hardening Treatment

4. 三、Applicable Standard
GB/T26146-2010 Double Eccentric Half Ball Valve
GB/T1047 Definition and use of DN (Nominal Diameter）pipe parts
GB/T1048 Definition and use of PN (Nominal Pressure）pipe parts
GB/T12224-2005 General Requirement of Cast Steel Valve
GB/T21465-2008 Valve Term
JB/T7928-1999 Supply Requirement of the General Valve
GB/T-12237-2007 Cast Steel Ball Valve for Petroleum,Petrochemical and Related industry
GB/T22652-2008 Welding Process Evaluation of Valve Seal Face
JB/T308 Design Method of Valve Model
GB/T2100 Corrosion Resistant Steel Castings for General Purpose
GB4208 Shell Protection Class (IP) Code
GB/T8923 Anti-Corrosion grade and Anti-rust Grade of Steel Surface Before Coating
GB/T9286 Colored Paint,Varnish and Film Thickness Test
GB/T12220 Markings of the General Valves
GB/T12221 Face to Face Dimension of Metal Sealing Valves
GB/T12223 Driving Device Connection of Part Turn Valves
GB12230-2005 General Valve- Stainless Steel Castings Technical Terms
GB/T13927 General Valve Pressure Test
GB/T9113 Integral Steel Pipe Flanges
GB/T9119 Plate, RF welding steel pipe flanges
JB/T106 Paints and Markings of Valves
JB/T5300 General Valve Material
JB/T-93-2008 Valve Parts, Wrench, Handles and Hand wheel
JB/T-1708-2010 Valve Parts，Packing Gland、Packing Bushing and Packing Plate
GB/T12220 Stainless steel bars
GB/T3452.1
Part 1 of O rubber seal ring for hydraulic gas movement: size series and
tolerance
JB/T10688-2006 Technical Conditions for polytetrafluoroethylene gasket
GB/T6739 Determination of Film Hardness by Pencil Test
GB/T8923 Corrosion Grade and Rust Grade of Steel Surface before Coating
GB/T11211
Determination of adhesive strength of vulcanized rubber and metal - Method of
drawing
JB/T-5296-1991 General Valve Test method of Flow Coefficient and Flow Resistance Coefficient
JB/T7927-1999 Valve Casting Steel Parts Appearance Requirement
GB/T-8531-1197 Technical Condition of Manual Device

5. 四、Advanced Performance Introduction
According to the principle and theoretical basis of the cam eccentricity
wedge, the unique pure alkali hemisphere valve for pure alkali has the
following unique features:
1、 The advanced design idea and design methods make the valve
have
the characteristics of small flow resistance coefficient and low
energy consumption.
The fluid flow inner the valve cavity is a complicated turbulent flow
process, its characteristic is irregular, dissipative, swirl and diffusion.
According to the mathematical model of Bernoulli equation, the motion of the fluid momentum
equation, continuity equation and mass conservation law and finite element analysis software ANSYS
to simulate the fluid flow field analysis, Solid works software was used to design the valve body, and
design and optimize the design of whole body, the channel of the valve, the fluid resistance coefficient
is small, nearly zero;
The simulation analysis of the fluid field is carried out
when the valve is 100% opened（Please see Surface
distribution of flow velocity at 100% opening of the valve )，
As shown in the figure, the highest speed appears in the red
part of the entrance，the velocity distribution gradient of the
whole flow channel is small，which is nearly in the middle
area，the value and color in the picture shows that the
overflow is smooth. The velocity distribution is more
uniform，the whole flow is more stable，both the above and
bellow side almost is symmetry.There is no obvious
increase in the flow velocity in the whole flow channel, and the local loss of pressure decreases
obviously.The maximum flow velocity in the flow field does not appear at the seat sealing surface.The
velocity in the valve seal is very low, so the wear to the valve is very small.Analyzed from the pressure
distribution chart，the part of the pressure gradient decrease obviously,under this condition,the flow
resistance coefficient is almost zero, so the energy consumption reduce is very low.
ANSYS 分 析
阀门三维

6. 2、 Unique double eccentric structure can cut off the solid crystallized mediums ， which is
specially used for anti-scaling valves for soda ash industry.
The opening and closing of the valve is achieved by valve disc rotation around valve stem
about 90°. Because of the double eccentric structure,when the semi ball open open about 5°from
the valve closing position,the left and right side semi ball spherical almost completely separate
from the valve sealing surface，so the wear between the valve seat and valve disc is very small.
The half ball valve is designed with eccentric structure，when the valve disc is closing，the valve
disc has a good wedge with the valve seat sealing face，which can perfectly cut solid particles
attached to the sealing surface of the valve disc.So the eccentric half ball valve has very perfect
anti-crystallization and anti-scaling performance.Following is our test of the shear force during the
semi ball valve opening and closing，The wire can be cut off when the valve is closed，Then, a
piece of paper is cut in the same position, the section of the paper is smooth, which proves that
there is no damage after the wire was cut off. In the soda ash industry, mother liquor is very easy
to crystallize and scaled,bur QUANSHUN double eccentric half ball valve can effectively solve
this problem.
Shear test with wire Shear test with paper The shearing face is smooth
The sealing is tight, and corrosion resistant by chloride radical, Scaring and
scaling not influence opening and shutting is the special feature of eccentric valve
specially for soda ash industry.
In the soda ash production process, because the ammoniacal brine has serious
corrosion, if the valve material is improper, the parts that contact with the medium,
especially the copper material is very easily affected by the corrosion of the medium and

7. the sealing performance is affected. Following picture is other manufacturer’s valves
installed on the soda ash plant, after application for a short time, the crystallization is very
serious.
QUANSHUN brand half ball valve is designed with corrosion resistance material, valve
body material is selected with SS316L castings, valve stem material is selected with
F316, valve disc and valve seat material is selected with C4 steel, and processed by
special hardening treatment, the sealing surface hardness is very high, the valve service
life is very long.