Flowserve NRG 16-50 User Manual

GESTRA Steam Systems

NRG 16-50
NRG 17-50
NRG 19-50
NRG 111-50

Installation Instructions 818954-01

Level Electrodes
NRG 16-50, NRG 17-50, NRG 19-50,
NRG 111-50

EN

English

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Contents

Page

Application

Usage for the intended purpose ..............................................................................................................4

Function .................................................................................................................................................4

Directives and Standards

Pressure Equipment Directive (PED) 97/23/EC ........................................................................................

Functional Safety acc. to IEC 61508 ........................................................................................................

VdTÜV Bulletin "Wasserstand 100" (= Water Level 100) ..........................................................................

ATEX (Atmosphère Explosible) ................................................................................................................. 5

Technical Data

NRG 16-50, NRG 17-50, NRG 19-50, NRG 111-50 ..................................................................................

Corrosion resistance ............................................................................................................................... 7

Sizing .....................................................................................................................................................7

Name plate / marking .............................................................................................................................8

Dimensions NRG 16-50, NRG 17-50, NRG 19-50 ....................................................................................

Dimensions NRG 111-50 ......................................................................................................................10

Functional Elements

NRG 16-50, NRG 17-50, NRG 19-50 ..................................................................................................... 11

NRG 16-50, NRG 17-50, NRG 19-50, NRG 111-50 four-pole connector ............................................11,12

NRG 16-50F, NRG 17-50F, NRG 19-50F, NRG 111-50F aluminium terminal box ..................................... 13

Key .......................................................................................................................................................14

Important Notes

Safety note ...........................................................................................................................................15

Scope of supply .................................................................................................................................... 15

Installation

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NRG 16-50, NRG 17-50, NRG 19-50, NRG 111-50, step 1 ..................................................................... 16

NRG 16-50, NRG 17-50, NRG 19-50, NRG 111-50, step 2 ..................................................................... 16

NRG 16-50F, NRG 17-50F, NRG 19-50F, additional information ..............................................................16

Tools .....................................................................................................................................................17

Examples of installation

NRG 16-50, NRG 17-50, NRG 19-50 ..................................................................................................... 18

NRG 111-50 .........................................................................................................................................19

Key .......................................................................................................................................................20

Contents – continued –

Page

Electrical Connection

Connection of level electrode ................................................................................................................ 21

NRG 16-50, NRG 17-50, NRG 19-50, NRG 111-50, with four-pole connector .........................................

NRG 16-50F, NRG 17-50F, NRG 19-50F, NRG 111-50F, with aluminium terminal box .............................

Wiring diagram ..................................................................................................................................... 22

Key .......................................................................................................................................................23

Tools .....................................................................................................................................................23

Commissioning, fault indication and remedy

NRG 16-50, NRG 17-50, NRG 19-50, NRG 111-50 ................................................................................23

Decommissioning

Disposal................................................................................................................................................23

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Application

Usage for the intended purpose

The level electrodes NRG 16-50, NRG 17-50, NRG 19-50 and NRG 111-50 are used in conjunction
with level switch NRS 1-50 as water level limiters for steam boiler plants and (pressurised) hot water
installations.
Water level limiters switch off the heating when the water level falls below the set minimum level
(low water).

Function

When the water level falls below the low level, the level electrode is exposed and a low level alarm is
triggered in the level switch NRS 1-50. This switchpoint “Low water level (LW)” is determined by the
length of the electrode tip.

The self-monitoring function ensures that an alarm will also be triggered if the electrode insulation is
contaminated or has developed a leak or if there is a malfunction in the electrical connection.

The level electrode is installed inside steam boilers, vessels or inlet lines of hot-water systems. The
protective tube mounted on site (see section Examples of Installation (pages 18, 19) ensures correct
functioning.

One level electrode NRG 1...-50 can be installed together with one GESTRA level electrode, one level
switch or transmitter for water level control and high level alarm in one single protection tube or level
pot.

If the level electrode is installed in an isolatable level pot outside the boiler, make sure that the
connecting lines are rinsed regularly. In addition, the logic unit SRL is required to monitor the purging
times and the purging sequence.

If the connecting lines for steam ≥ 40 mm and water ≥ 100mm, the installation is considered to be
internal. In this case the rinsing processes do not have to be monitored.

Directives and Standards

Pressure Equipment Directive (PED) 97/23/EC

Water level limiters are safety accessories as defined in the Pressure Equipment Directive (PED). The
level electrode NRG 1...-50 in conjunction with level switch NRS 1-50 is EC type approved according
to EN 12952/EN 12953. These Directives state, among other things, the requirements made on limiting
systems and equipment for steam boiler plants and (pressurised) hot-water installations.

Functional Safety acc. to IEC 61508

The level electrodes NRG 1...-50 / NRG 16-36 are certified acc. to IEC 61508 only if used in
combination with level switch NRS 1-50.
This standard describes the functional safety of safety-related electrical/electronic/programmable
electronic systems.

The equipment combination NRG 1...-50 or NRG 16-36 + NRS 1-50 corresponds to a type B
subsystem with Safety Integrity Level (SIL) 3.

VdTÜV Bulletin “Wasserstand 100” (= Water Level 100)

The level electrodes NRG 1-50, NRG 1...-11 and NRG 16-36 in conjunction with the level switch
NRS 1-50 are type approved according to the VdTÜV Bulletin “Water Level 100”.

The VdTÜV Bulletin “Wasserstand (=Water Level) 100” specifies the requirements made on water level
control and limiting equipment for boilers.

ATEX (Atmosphère Explosible)

The level electrodes NRG 1...-50, NRG 1...-11 and NRG 16-36 are simple items of electrical equipment
as specified in EN 60079-11 section 5.7. According to the European Directive 94/9/EC the equipment
must be equipped with approved Zener barriers if used in potentially explosive areas. Applicable in
Ex zones 1, 2 (1999/92/EC). The equipment does not bear an Ex marking.
The suitability of the Zener barriers is certified in a separate document.

Note that the requirements of the IEC 61508 are not met if the NRG 1...-50, NRG 1...-11,
NRG 16-36 + Zener barriers + NRS 1-50 are interconnected!

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Technical Data

NRG 16-50, NRG 17-50, NRG 19-50, NRG 111-50

Service pressure

NRG 16-50: PN 40, 32 bar at 238 °C
NRG 17-50: PN 63, 60 bar at 275 °C
NRG 19-50: PN 160, 100 bar at 311 °C
NRG 111-50: PN 320, 183 bar at 357 °C

Mechanial connection

Screwed ¾" to EN ISO 228-1 (NRG 16-50, NRG 17-50, NRG 19-50)
Screwed 1" to EN ISO 228-1 (NRG 111-50)

Materials

Sheath: 1.4301, X5 CrNi18-10
Screw-in body: 1.4571, X6CrNiMoTi17-12-2 (NRG 16-50, NRG 17-50, NRG 19-50)
Screw-in body: 1.4529, X1NiCrMoCuN25-20-7 (NRG 111-50)
Measuring electrode: 1.4571, X6CrNiMoTi17-12-2 (NRG 16-50, NRG 17-50, NRG 19-50)
Measuring electrode: 1.4122, X39CrMo17-1 (NRG 111-50)
Electrode tip: 1.4401, X5CrNiMo17-12-2
Electrode insulation: Gylon

®

(NRG 16-50, NRG 17-50, NRG 19-50)
Electrode insulation: Special ceramic (NRG 111-50)
NRG 1...-50: Four-pole connector: polyamid (PA)
NRG 1...-50F: Terminal box 3.2161 G AlSi8Cu3

Lengths supplied

500 mm, 1000 mm, 1500 mm, 2000 mm, 2500 mm, 3000 mm
ph value

Max. admissible: 10 (NRG 111-50)

Electrical connection

NRG 1...-50:

Four-pole connector, cable glands M 16

NRG 1...-50F: Terminal box made from aluminium, cable gland M 20

Protection

IP 65 to EN 60529

Max. admissible ambient temperature

70°C

Weight

Approx. 1.2 kg (without extension) (NRG 16-50, NRG 17-50, NRG 19-50)
Approx. 2.1 kg (without extension) (NRG 16-50F, NRG 17-50F, NRG 19-50F)
Approx. 1.8 kg (without extension) (NRG 111-50)
Approx. 2.7 kg (without extension) (NRG 111-50F)

Approvals

EC Prototype approval PED Pressure Equipment Directive 97/23/EC, EN 12952-11, EN 12953-09:
Requirements made on limiting equipment for boilers.

Functional Safety SIL 3 IEC 61508:
Functional safety of safety-related electrical/electronic/programmable
electronic systems

TÜV type approval VdTÜV Bulletin “Wasserstand 100” (= Water Level 100):
Requirements made on water level limiting & control equipment.

Type approval no. TÜV · SWB / SHWS · XX-XXX
(see name plate)

Gylon® is a registered trademark of Garlock Sealing Technologies, Palmyra NY, USA

Technical Data – continued –

Corrosion resistance

If the equipment is used for the intended purpose, its safety is not impaired by corrosion.

Sizing

The body is not designed for pulsating loads. Welds and flanges are designed to withstand dynamic
loading (bending and alternative stress). The dimensional allowances and anti-corrosive additives
reflect the latest state of the technical art.

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Technical Data – continued –

Name plate / marking

Equipment designation Safety note

Disposal note
Pressure rating, thread type,

material number, type approval number
CE marking

Fig. 1

Manufacturer

Serial number

Safety note

Equipment designation
Pressure rating, thread type, material

number

Pressure/temperature rating

CE Marking, type approval

Fig. 2

Disposal note

Manufacturer

Serial number

Fig. 3