GESTRA RK 86 and RKE 86 DISCO non-return valves are designed to prevent the return flow of fluids in piping systems. These wafer-type valves are installed by sandwiching between flanges and feature a closing spring that allows for installation in any position. They are suitable for liquid, gas, and steam applications across various industries, including pure steam installations and pharmaceuticals when specified in the pickled version.

Technical Description

The series consists of the RK standard design and the RKE design, which is specifically tested for use as an end valve (e.g., vacuum breakers). The RK 86 features a self-centering valve body with patented fixed centering cams (DN 15-100) to ensure accurate alignment between flanges. For larger sizes (DN 125-200), an adjusted diameter and eyebolts simplify installation.

Potentially Explosive Atmospheres

RKE equipment is not suitable for use in potentially explosive atmospheres. Standard RK equipment does not have its own ignition source, but electrostatic discharge must be managed by the system manufacturer. All standard RK 86 units are fitted with an M8 antistatic connection.

Pressure/Temperature Ratings

Type	Pressure [barg]	-10°C	100°C	200°C	300°C	400°C	550°C
RK/RKE 86 (DIN PN40)	p [barg]	40.0	37.4	33.6	27.8	-	-
RK/RKE 86A (DIN PN40)	p [barg]	40.0	38.1	30.2	25.8	23.5	20.7
RK/RKE 86 (ASME CL300)	p [barg]	51.1	46.6	43.8	39.8	-	-
RK/RKE 86A (ASME CL300)	p [barg]	49.6	42.2	35.7	31.6	29.4	25.1

Note: Ratings for RK 86A above 300°C require the exclusion of intercrystalline corrosion risks.

Valve Seat Options

Seat Material	Temp Min [°C]	Temp Max [°C]	Application	Leakage Rate
Metal-to-metal (RK 86)	-10	350/400	Liquid, gas, steam	EN 12266-1, Rate C
Metal-to-metal (RK 86A)	-200	550	Liquid, gas, steam	EN 12266-1, Rate C
EPDM	-40	150	Water, condensate, steam	EN 12266-1, Rate A
FPM	-25	200	Mineral oil, gas, air	EN 12266-1, Rate A
PTFE	-190	250	Aggressive fluids	EN 12266-1, Rate C

Materials

Component	RK 86 (DN 15-100)	RK 86A (DN 15-100)	RK 86 (DN 125-200)	RK 86A (DN 125-200)
Body	1.4317 (Cr Steel)	1.4408 (SS)	1.0619 (Cast Steel)	1.4408 (SS)
Valve Disk/Cone	1.4571	1.4571	1.4006	1.4404
Closing Spring	1.4571	1.4571	1.4571	1.4571

Opening Pressures (mbar)

DN	Without Spring (↑)	Flow Direction With Spring (↑)	Flow Direction With Spring (→)	Flow Direction With Spring (↓)
15-25	2.5	10	7.5	5
50	4.5	14	9.5	5
100	6.5	18	11.5	5
200	13.5	37	23.5	10

Performance and Sizing

The chosen non-return valve must ensure that the minimum volume flowrate keeps the valve disk in the stable open position. In valves equipped with a stroke limiter, the required minimum volume flowrate is reduced by 40%.