Product Overview

Spirax Sarco SP7 is an electronically configurable smart digital positioner designed to mount directly onto pneumatic linear or rotary actuators conforming to NAMUR standards. It regulates control valve positioning by ensuring exact proportionality between the electrical control signal (4-20 mA or fieldbus) and actuator stroke, eliminating control loop deviation in industrial steam and process fluid applications.

Constructed with an IP65 die-cast aluminum housing finished in anti-corrosive paint, the unit resists mechanical vibration up to 10 g at 80 Hz. The product series includes three main communication variants: SP7-10 (standard 4-20 mA with Local Communication Interface [LCI], optional HART 5 or HART 7), SP7-11 (PROFIBUS PA), and SP7-12 (FOUNDATION Fieldbus). The instrument incorporates an integrated LCD display, pushbuttons for local setup, and an internal I/P converter utilizing a 3/3-way valve system for low air consumption.

Key Features

• Fully automatic commissioning with standard auto-adjustment routines (ADJ_LIN for linear actuators and ADJ_ROT for rotary actuators), determining stroke limits and control parameters without external tools.
• Vibration compensation and shock resistance up to 10 g from 10 to 80 Hz with positioning deviation limited to <= 1%.
• Multi-protocol communications support across models: 4-20 mA with LCI and HART 5/7 (SP7-10), PROFIBUS PA (SP7-11), or FOUNDATION Fieldbus (SP7-12).
• Flexible failure modes on signal or electrical power loss: single-acting fail-safe (venting), single-acting fail-freeze, double-acting fail-safe, or double-acting fail-freeze.
• Analog-to-digital conversion resolution exceeding 16,000 steps with a 20 ms sampling rate on 4-20 mA, HART, and PROFIBUS PA models.
• Optional modular position feedback upgrades: plug-in 4-20 mA analog feedback board (AO), dual software digital switches (SW1/SW2), or mechanical limit switch assemblies (Pepperl+Fuchs SJ2-SN inductive proximity switches or 24 V microswitches).
• Low steady-state air consumption below 0.03 kg/h (0.015 scfm) independent of supply pressure.
• Certified for hazardous area installations under ATEX, IECEx, NEPSI, UKEX, and INMETRO intrinsically safe standards (Ex ib IIC T6/T4).

Technical Specifications

Specification	SP7-10 (4-20 mA / HART)	SP7-11 (PROFIBUS PA)	SP7-12 (FOUNDATION Fieldbus)
Input Signal	4 to 20 mA (split range min 8 mA)	PROFIBUS PA (9 to 32 Vdc)	FOUNDATION Fieldbus (9 to 32 Vdc)
Input Impedance / Current	Max 485 +/- 15 Ohm (at 20 mA)	10.5 mA (15 mA fault current)	11.5 mA (15 mA fault current)
Supply Air Pressure	1.4 to 6.0 bar (20 to 90 psi)	1.4 to 6.0 bar (20 to 90 psi)	1.4 to 6.0 bar (20 to 90 psi)
Compressed Air Quality	ISO 8573-1:2010 Class 3:3:3	ISO 8573-1:2010 Class 3:3:3	ISO 8573-1:2010 Class 3:3:3
Output Pressure Range	0 to 100% supply pressure	0 to 100% supply pressure	0 to 100% supply pressure
Stroke Range (Linear)	20 mm to 150 mm (-28 to 28 deg)	20 mm to 150 mm (-28 to 28 deg)	20 mm to 150 mm (-28 to 28 deg)
Angular Range (Rotary)	55 to 90 deg (-57 to 57 deg)	55 to 90 deg (-57 to 57 deg)	55 to 90 deg (-57 to 57 deg)
Action Formats	Single-acting / Double-acting	Single-acting / Double-acting	Single-acting / Double-acting
Operating Temperature	-40 to 85 deg C	-40 to 85 deg C	-40 to 85 deg C
Positioning Deviation	<= 0.5%	<= 0.5%	<= 0.5%
Tolerance Band	0.3 to 10%, adjustable	0.3 to 10%, adjustable	0.3 to 10%, adjustable
Configurable Dead Zone	0.1 to 10%, adjustable	0.1 to 10%, adjustable	0.1 to 5%, adjustable
AD-Conversion Resolution	> 16,000 steps	> 16,000 steps	> 16,000 steps
Sampling Frequency	20 ms	20 ms	Fieldbus cycle
Temperature Effect	<= 0.5% per 10 K	<= 0.5% per 10 K	<= 0.5% per 10 K
Vibration Resistance	<= 1% up to 10 g and 80 Hz	<= 1% up to 10 g and 80 Hz	<= 1% up to 10 g and 80 Hz
Enclosure Rating	IP65 (optional IP66 / NEMA 4X)	IP65 (optional IP66 / NEMA 4X)	IP65 (optional IP66 / NEMA 4X)
Pneumatic Connections	1/4”-18 NPT female	1/4”-18 NPT female	1/4”-18 NPT female
Electrical Cable Entries	1/2”-14 NPT or M20 x 1.5	1/2”-14 NPT or M20 x 1.5	1/2”-14 NPT or M20 x 1.5
Bare Positioner Weight	1.7 kg	1.7 kg	1.7 kg
Explosion Protection Ratings	ATEX/IECEx/NEPSI/UKEX Ex ib IIC T6/T4	ATEX/IECEx/NEPSI/UKEX Ex ib IIC T6/T4	ATEX/IECEx/NEPSI/UKEX Ex ib IIC T6/T4

Applications

• Linear control valves operated by Spirax Sarco pneumatic diaphragm actuators:
  • PN9000 Series (PN9100, PN9200, PN9300, and PN9400)
  • TN2000 Series (TN2150, TN2270, TN2300, and TN2400)
  • PN1600 Series
  • PNS3000 and PNS4000 Series
  • PN3000 Spring-Extend and PN4000 Spring-Return Series
  • PN5000 and PN6000 Series (with UBC bracket adapter)
• Rotary industrial valves operated by quarter-turn pneumatic actuators:
  • Spirax Sarco BVA300 series rotary actuators (via AKR14 mounting kit)
  • Standard quarter-turn actuators meeting VDI/VDE 3845
• Industrial process valves across energy and utility loops:
  • Spira-trol two-port globe valves (DN15 to DN300)
  • QL three-port mixing and diverting valves (DN15 to DN300)
  • Clean-steam and sanitary valves including LE, LEA, and Steri-trol series (DN15 to DN100)
  • General-purpose KE, KEA, and C-series control valves

Pneumatic Installation and Air Quality

Operation requires clean, dry, oil-free instrument air conforming to ISO 8573-1:2010 Class 3:3:3 (maximum particle size 5 um, particle density <= 5 mg/m3, oil concentration <= 1 mg/m3, and pressure dew point at least 10 K below ambient operating temperature). Operating air supply pressure ranges between 1.4 and 6.0 bar (20 to 90 psi). Supply pressure must not exceed 6.0 bar under any fault condition.

All pneumatic ports are tapped 1/4”-18 NPT female on the right side of the housing, utilizing 12 x 1.75 mm tubing:

• IN: Instrument air supply inlet (1.4 to 6 bar).
• OUT1: Controlled output pressure to actuator chamber.
• OUT2: Secondary output pressure utilized on double-acting actuators.

On double-acting actuators with spring-return mechanics, internal spring compression during operation can generate chamber pressures substantially exceeding supply pressure. In these installations, install a pressure compensation check valve with an opening pressure < 250 mbar (< 3.6 psi) between the springless chamber and the air supply line to vent excess pressure safely.

On-Board Display and Configuration

The local user interface comprises an LCD display with a 4-digit 7-segment numerical line showing physical units (deg C, %, mA) and an 8-character 14-segment status line displaying operating parameter codes. Four pushbuttons (ENTER, MODE, UP, and DOWN) provide menu control directly in the field without handheld communicators.

Four standard operating levels are accessible:

• Mode 1.0: Control operation with automatic continuous adaptation of control parameters.
• Mode 1.1: Control operation with fixed control parameters determined during auto-adjustment.
• Mode 1.2: Manual valve positioning within the calibrated operating stroke range.
• Mode 1.3: Manual valve positioning across the physical measuring range of the position sensor.

Mounting Kits and Accessories

• Linear Actuator Mounting Kits (NAMUR / IEC 534):
  • AKL10 (0.78 kg): Standard central mounting kit for PN9100, PN9200, PN9300, TN2150, PN3000, and PN4000 on DN15 to DN100 valves.
  • AKL11: Mounting kit for PN1600 series and large PN5000/PN6000 installations.
  • AKL17: Heavy-duty kit for PN9400, TN2270, TN2300, and TN2400 actuators on DN125 to DN300 valves.
• Rotary Actuator Mounting Kits (VDI/VDE 3845):
  • AKR13: 80 x 20 mm interface.
  • AKR14 (0.40 kg): 80 x 30 mm interface (standard selection for BVA300 actuators).
  • AKR15: 130 x 30 mm interface.
  • AKR16: 130 x 50 mm interface.
• Pressure Gauge Blocks:
  • GBS6A: Single-acting gauge block calibrated to 6 bar (1/4” NPT, 0.28 kg).
  • GBD6A: Double-acting gauge block calibrated to 6 bar (1/4” NPT, 0.32 kg).
  • GBS06A / GBD06A: Single and double-acting blocks calibrated to 0.6 MPa.
• Routine Maintenance:
  • Replacement pneumatic internal filter kit: Part Number 3440580.