Ball check valves

Innovative SZUSTER system elbow check valves are the first, which have a fully open position and a constant local resistance coefficient starting from the flow rate of 0.7 m/s.
SZUSTER system ball check valves, due to the unique characteristics and usable features, are widely used in ordinary pumping stations and pumping stations with separation of solids and pumps. Thanks to safety and ease of use (the possibility of placing the cover in service position), they are also valued by Users of sewer systems.
SZUSTER system’s solution is also a water check valve used in hydrophore sets and water wells.
Technical data
- Range of available diameters: DN32 – DN300.
- Pressure rated to PN 1.6 MPa (all valves are tested to PN 1.0 MPa leak test / PN 1.6 MPa hydrostatic shell test).
- Medium temperature: max 40ºC (temporarily to 60ºC).
- Painted with a 200 μm thick coat of epoxy paint, RAL 5015 (optional: 300 μm, other colours).
- Flanges complying with EN 1092-2.
- EN 12050-4 tests and requirements.
SZUSTER System Elbow Ball Check Valves type ESK 01 or COMBI 01 (with threaded connection), and ESK 11 or COMBI 11 (with flange connection) are used for self-actuating protection against reversible wastewater flow from the backflow of the medium the moment the pump/compressor stops working (except ESK 11.L – when the pump/compressor starts working). An additional function of type COMBI is the possibility of manual cutting off at any time the flow of fluid by closing the knife gate valve, which is an integral part of the construction. Elbow check valves are used in wastewater systems with or without the fecal matter up to the the temperature of 40ºC and a pH range of 4-8.
In comparison with traditional ball check valves and flap check valves our product provides many benefits.
For Pumps
- Enables more compact construction of the pump canopy.
- Low service time – our ball check valves take less than 15 minutes to service.
- Quick replacement time – customers can quickly replace the valve balls themselves without damaging the equipment.
For Pumping Stations
- Space saving – our valves enable space saving in a pumping station therefore giving the possibility of using a much smaller tank.
- Quick replacement time – customers can quickly replace valve balls themselves without damaging the equipment.
- Full opening at the velocity of 0.7 m/s – the SZUSTER system check valves are fully opened at the velocity of 0.7 m/s, thereby enabling the efficient work of the customer’s system.
- Significant reduction of vibration – our check valves successfully reduce vibrations thereby making the system work more quietly.
For Waterworks
- Full opening at the velocity of 0.7 m/s – fully open position and constant local resistance coefficient, starting from the flow rate of 0.7 m/s.
- Easy access to valves interior and the ball which enables:
– placing the cover in the so-called servicing position
– inspection of the inlet pipeline (including the pump impeller) and inspection of the pressure pipeline - Reduction of vibrations making the system work more quietly.
For Engineers
- Combined solution – a two-in-one compact solution (elbow, check valve) or even a three-in-one compact solution (elbow, check valve, knife gate valve).
- Fully open position and constant local resistance coefficient, starting from the flow rate of 0.7 m/s.
- Reduction of vibrations making the system work more quietly.
Product development is our priority. We listen carefully to the opinion of our customers, thus constantly creating new versions and improvements such as quasi balls – used by manufacturers of lift stations with the separation of solids.
Additional options of ball check valves
Type of check valve | Characteristics | Examples of application |
Long version (L) | The valve in L verison has a free passage for the ball with a nominal diameter of the valve |
Pumping station with separation of solid parts, pneumatic pumping stations. |
Version with floating ball (F) | The valve in F verison is equipped with a ball, so-called “floating” ball, with a specific weight of approx 0.8 g/cm3 |
Backwater protection. |
Version with quasi ball (Q) | The valve in Q version is equipped with a quasi floating ball with a specific weight of approx 1.02 g/cm3 | Pumping stations, pumping stations with separation of solids, pumps with inverter |
Version with drainage (D) | The valve in D version is equipped with drain plug for valve drainage |
Pumps, dry lift stations, gravity installations with anti reflux valves |
Table of options
DN | PN 10 | PN 16 | Cast Iron | Ductile Iron | Long version (L) | Floating ball (F) | Quasi ball (Q) | Drainage (D) |
Type ESK 01 – threaded | ||||||||
32 | regular | option | regular | n/a | n/a | n/a | n/a | n/a |
40 | regular | option | regular | n/a | n/a | n/a | n/a | n/a |
50 | regular | option | regular | n/a | n/a | option | n/a | n/a |
Type ESK 11 – flanged | ||||||||
50 | regular | option | regular | n/a | n/a | option | n/a | n/a |
65 | regular | option | regular | n/a | n/a | option | n/a | n/a |
80 | regular | option | regular | n/a | option | option | option | option |
100 | regular | option | regular | n/a | option | option | option | option |
150 | regular | option | n/a | regular | n/a | option | option | option |
200 | regular | option | n/a | regular | option | option | option | option |
250 | regular | option | n/a | regular | n/a | option | n/a | option |
300 | regular | option | n/a | regular | n/a | option | n/a | option |
Typ COMBI 01 – threaded inlet, flanged outlet | ||||||||
50 | regular | n/a | option | n/a | n/a | option | n/a | n/a |
Typ COMBI 11 – flanged | ||||||||
50 | regular | n/a | option | n/a | n/a | option | n/a | n/a |
80 | regular | n/a | option | n/a | n/a | option | option | option |
100 | regular | n/a | option | n/a | n/a | option | option | option |
Typ COMBI 11 – flanged, oval version | ||||||||
50.O | regular | n/a | option | n/a | n/a | option | n/a | n/a |
SZUSTER system elbow check valves are made from cast iron (DN32 – DN150) or ductile iron (DN200 – DN300). Their optimal ranges of working pressure are adapted to the pressure occurring in the sewage systems (PN 1.0 MPa or PN 1.6 MPa – different for each type).
Ball check valves dimensions

DN | L | H | D | d | K | l x n | S | Gw | ζ* | Masa |
(mm) | (“) | (kg) | ||||||||
Type ESK 01 – threaded | ||||||||||
32 | 80 | 80 | 55 | 1 1/4 | 1,4 | 1,8 | ||||
40 | 100 | 100 | 60 | 1 1/2 | 3,9 | 2,3 | ||||
50 | 100 | 100 | 75 | 2 | 2,4 | 4,2 | ||||
Type ESK 11 – flanged | ||||||||||
50 | 100 | 100 | 165 | 99 | 125 | ø 19 x 4 | 2,4 | 8,3 | ||
65 | 140 | 140 | 185 | 118 | 145 | ø 19 x 4 | 1,5 | 10,9 | ||
80 | 165 | 165 | 200 | 133 | 160 | ø 19 x 8 | 1,7 | 16,7 | ||
100 | 200 | 200 | 220 | 156 | 180 | ø 19 x 8 | 1,6 | 25,4 | ||
150 | 280 | 280 | 285 | 211 | 240 | ø 23 x 8 | 1,6 | 49,6 | ||
200 | 350 | 350 | 340 | 266 | 295 | ø 23 x 8 (12) | 1,6 | 83,7 | ||
250 | 425 | 425 | 400 | 319 | 350 | ø 23 x 12 | 1,5 | 131 | ||
300 | 510 | 510 | 455 | 375 | 400 | ø 23 x 12 | 1,5 | 197 | ||
Type ESK 11 – flanged, long version – L | ||||||||||
80 | 200 | 200 | 200 | 133 | 160 | ø 19 x 8 | 0,9 | 17,7 | ||
100 | 250 | 250 | 220 | 156 | 180 | ø 19 x 8 | 1,1 | 29,6 | ||
200 | 400 | 400 | 340 | 266 | 295 | ø 23 x 8 | 1,6 | 78,1 |

DN | L | H | D | d | K | l x n | S | Gw | ζ* | Masa |
(mm) | (“) | (kg) | ||||||||
Type COMBI 01 – theaded inlet, flanged outlet | ||||||||||
50 | 110 | 100 | 165 | 102 | 125 | ø 19 x 4 | 75 | 2 | 2,6 | 8,6 |
Type COMBI 11 – flanged | ||||||||||
50 | 110 | 100 | 165 | 102 | 125 | ø 19 x 4 | 75 | 2,6 | 12,8 | |
65 | 155 | 140 | 180 | 122 | 145 | ø 19 x 4 | 1,5 | 16,8 | ||
80 | 165 | 165 | 200 | 138 | 160 | ø 19 x 8 | 1,8 | 24 | ||
100 | 200 | 200 | 220 | 160 | 180 | ø 19 x 8 | 1,7 | 32,7 | ||
Type COMBI 11 – flanged, oval version – O | ||||||||||
50.O | 115 | 100 | 148 | – | 114 | ø 18 x 2 | 2,4 | 10,6 |
Elbow ball check valves installation method

Our valve substitutes an elbow on the pipeline and eliminates one flange joint (COMBI check valve eliminates 2 flange connections). It is located at a right angle and connects a vertical pipe with the horizontal one. Please note that the technology of ESK check valves allows using them on surface and underground installations.
SZUSTER system elbow check valves, type ESK or COMBI can be mounted in horizontal and vertical drainage systems in the positions as shown.