Grundfos Pressurisation Range – PHT Top-Up Units & GT Expansion Vessels
The Grundfos pressurisation range provides complete solutions for maintaining system pressure in sealed heating and cooling installations. Combining reliable PHT (Pressure Holding Top-up) units with advanced control systems and GT expansion vessels, these intelligent systems ensure fluid remains air-free while maintaining optimal pressure—maximizing efficiency, reducing maintenance costs, and extending system life.
As an authorized Grundfos Water Pump Dealer in Dubai, we supply the complete Grundfos pressurisation range with genuine warranty and technical support across the UAE.
Product Type Key
| Code | Description |
|---|---|
| PHT | Pressure Holding Top-up |
| A | Second generation |
| N | Narrow format wall mounted |
| D | Deep format wall mounted |
| F | Floor standing unit |
| T | Twin system unit |
| V | Glycol (additional valves and tank) |
| 1/2 | Number of pumps |
| 25/30/50/80/100 | Max fill pressure (2.5/3.0/5.0/8.0/10.0 bar) |
MINI PRESSURISATION UNITS
Mini Monopress & Mini Duopress
Compact wall-mounted units for small heating or cooling installations in large domestic dwellings or small industrial/commercial applications.
Operating Specifications:
| Parameter | Specification |
|---|---|
| Electrical Supply | 230V +10/-6% |
| Fuse Protection | 2 A |
| Noise Level | <65 dB(A) |
| Liquid Temperature | +3°C to +40°C |
| Usage | Indoor |
| Ambient Temperature | Up to +40°C |
| Relative Humidity | Up to 95% non-condensing |
| Max Inlet Pressure | 6 bar |
| Generated Pressure | 2.5 bar |
Mini Pressurisation Range:
| Product Name | Pump Qty | Max Cold Fill (bar) | Power (W) | Product Code |
|---|---|---|---|---|
| Mini Monopress Control | 1 | 2.5 | 25 | MMP50801 |
| Mini Monopress Control + Hi & Low | 1 | 2.5 | 25 | MMP50802 |
| Mini Duopress Control + Hi & Low | 2 | 2.5 | 25 | MDP50802 |
Dimensions:
| Model | Width (mm) | Depth (mm) | Height (mm) | Break Tank | Dry Weight (kg) |
|---|---|---|---|---|---|
| Mini Monopress | 350 | 200 | 300 | 4.5 L | 8.5 |
| Mini Duopress | 350 | 200 | 300 | 4.5 L | 11 |
Connections: System ¼”, Mains ½”, Drain ¾”
Standard Features:
- Powder coated casing
- Front mounted system pressure gauge
- Make-up tank with system filling valve assembly
- 0.7 to 2.5 bar pressure pump
- Pressure control switch
- WRAS approved filling valve (WRC byelaw 11 compliant)
PHT A SERIES – PRESSURE HOLDING TOP-UP RANGE
Common PHT A Range Data
| Parameter | Specification |
|---|---|
| Unit Rating | PN10 |
| Electrical Requirements | 230V, 50Hz, 1 Phase |
| Noise Output | <75 dB(A) |
| Fluid Category Protection | 5 AB Weir Overflow Air Gap |
| Maximum System Temperature | 85°C |
| Ambient Temperature | Up to 40°C |
| Relative Humidity | 95% non-condensing |
Installation Location: Return header on suction side of circulating pump (system neutral point)
PHT A N-Series (Narrow Format Wall Mounted)
Suitable for large residential or small commercial applications (system volume up to 2,500 litres).
| Product Name | Pump Qty | Max Cold Fill (bar) | Power (W) | Current (A) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| PHT A N130 | 1 | 3 | 28 | 0.12 | 12 | 99264904 |
| PHT A N230 | 2 | 3 | 28 | 0.12 | 13 | 99264947 |
Dimensions: 240 × 152 × 482 mm | Break Tank: 2 Litre | Connections: System ¼”, Mains ½”, Drain ¾”
PHT A D-Series (Deep Format Wall Mounted)
Available in single and twin pump configurations with 3.6 litre break tank.
Single Pump Units:
| Product Name | Pump Qty | Max Cold Fill (bar) | Power (kW) | Current (A) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| PHT A D125 | 1 | 2.5 | 0.41 | 1.83 | 20 | 99264948 |
| PHT A D150 | 1 | 5 | 0.9 | 3.94 | 21 | 99264949 |
Dimensions (Single): 260 × 277 × 522 mm
Twin Pump Units (Duty/Standby with Auto Switchover):
| Product Name | Pump Qty | Max Cold Fill (bar) | Power (kW) | Current (A) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| PHT A D225 | 2 | 2.5 | 0.41 | 1.83 | 29 | 99264951 |
| PHT A D250 | 2 | 5 | 0.9 | 3.94 | 30 | 99264952 |
Dimensions (Twin): 440 × 302 × 522 mm | Break Tank: 3.6 Litre | Connections: System ½”, Mains ½”, Drain ¾”
PHT A F-Series (Floor Standing)
For medium-sized commercial systems with 17.5 litre break tank.
| Product Name | Pump Qty | Max Cold Fill (bar) | Power (kW) | Current (A) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| PHT A F125 | 1 | 2.5 | 0.41 | 1.83 | 31 | 99264963 |
| PHT A F150 | 1 | 5 | 0.9 | 3.94 | 32 | 99264964 |
| PHT A F180 | 1 | 8 | 1.15 | 5.2 | 37 | 99264965 |
| PHT A F225 | 2 | 2.5 | 0.41 | 1.83 | 38 | 99264966 |
| PHT A F250 | 2 | 5 | 0.9 | 3.94 | 39 | 99264967 |
| PHT A F280 | 2 | 8 | 1.15 | 5.2 | 46 | 99264968 |
Dimensions: 470 × 332 × 832 mm | Break Tank: 17.5 Litre | Connections: System ½”, Mains ½”, Drain ¾”
PHT A T-Series (Floor Standing Twin System)
Ideal where space restrictions require two systems in a single enclosure.
| Product Name | Pump Qty | Max Cold Fill (bar) | Power (kW) | Current (A) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| PHT A T225 | 2 | 2.5 | 0.41 | 1.83 | 41 | 99264969 |
| PHT A T250 | 2 | 5 | 0.9 | 3.94 | 42 | 99264970 |
Dimensions: 470 × 333 × 850 mm | Break Tank: 17.5 Litre | Connections: System 2×½”, Mains ½”, Drain ¾”
PHT A V-Series (Floor Standing with Glycol Make-Up)
Automatically adds glycol from dedicated tank at predetermined rate during top-up, reducing manual intervention.
| Product Name | Pump Qty | Max Cold Fill (bar) | Power (kW) | Current (A) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| PHT A V225 | 2 | 2.5 | 0.41 | 1.83 | 56 | 99264977 |
| PHT A V250 | 2 | 5 | 0.9 | 3.94 | 58 | 99264979 |
Dimensions: 670 × 333 × 852 mm | Break Tank: 3.6 L | Glycol Tank: 17.5 L | Connections: System ½”, Mains ½”, Drain ¾”
PHT A Series Standard Features
- Simple, security coded user interface
- Event logging
- Low water level sensor
- Durable powder coated enclosure
- Pressure transducer control
- Password protection
- LED display
- Pump trip monitoring
- System flood detection
- Service due reminder
- Adjustable pressure differential
- Manual run capability
- Hours run counter
- Pump activation counter
- Alarm logging
- Anti-seize run (30/60/90 days)
- Automatic duty rotation (twin pump units)
- USB software update port
- Audible alarm
- Status LED
- Volt-free contacts (8A/230V)
- System interlock
- Programmable outputs
Options:
- High water level sensor
- BACnet communications (via CIM card)
- Modbus communications (via CIM card)
GT EXPANSION VESSELS
Why Sealed Expansion Vessels?
Expansion vessels protect closed water heating and cooling systems from excessive pressure. The rubber diaphragm separates water from the nitrogen gas pocket, preventing air transfer into the system, reducing corrosion, and eliminating the need for regular draining and bleeding.
GT-HR 6 Bar Rated Expansion Vessels
Suitable for sealed heating and chilled systems.
Features:
- Low-carbon sheet steel shell
- Non-replaceable SBR rubber diaphragm
- Liquid compartment with polypropylene liner (PP)
- Threaded connection
- 50% vessel efficiency
| Product Name | Pressure (bar) | Volume (L) | Diameter (mm) | Height (mm) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| GT-HR-8 PN6 | 6 | 8 | 206 | 305 | 1.9 | 96573376 |
| GT-HR-12 PN6 | 6 | 12 | 280 | 275 | 2.6 | 96573377 |
| GT-HR-18 PN6 | 6 | 18 | 280 | 380 | 3.5 | 96573378 |
| GT-HR-25 PN6 | 6 | 25 | 280 | 490 | 4.6 | 96573390 |
| GT-HR-35 PN6 | 6 | 35 | 354 | 460 | 5.4 | 96573393 |
| GT-HR-50 PN6 | 6 | 50 | 409 | 493 | 12.5 | 96573395 |
| GT-HR-80 PN6 | 6 | 80 | 480 | 565 | 17 | 96573396 |
| GT-HR-100 PN6 | 6 | 100 | 480 | 670 | 20.5 | 96573397 |
| GT-HR-140 PN6 | 6 | 140 | 480 | 912 | 28.6 | 96573398 |
| GT-HR-200 PN6 | 6 | 200 | 634 | 758 | 36.7 | 96573399 |
| GT-HR-250 PN6 | 6 | 250 | 634 | 888 | 45 | 96573400 |
| GT-HR-300 PN6 | 6 | 300 | 634 | 1092 | 52 | 96573401 |
| GT-HR-400 PN6 | 6 | 400 | 740 | 1102 | 65 | 96573403 |
| GT-HR-500 PN6 | 6 | 500 | 740 | 1312 | 79 | 96573404 |
| GT-HR-600 PN6 | 6 | 600 | 740 | 1531 | 85 | 96573405 |
| GT-HR-800 PN6 | 6 | 800 | 740 | 1996 | 103 | 96573407 |
| GT-HR-1000 PN6 | 6 | 1000 | 740 | 2406 | 120 | 96573408 |
GT-U+ 10 Bar Rated Expansion Vessels
Features:
- Low-carbon sheet steel shell
- Replaceable butyl bladder
- Built-in pressure gauge
- Threaded connection
- WRAS approved
- 50% vessel efficiency
| Product Name | Pressure (bar) | Volume (L) | Diameter (mm) | Height (mm) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| GT-U+ 100 PN10 | 10 | 100 | 453 | 983 | 76.5 | 99082696 |
| GT-U+ 150 PN10 | 10 | 150 | 504 | 1056 | 91.5 | 99082697 |
| GT-U+ 200 PN10 | 10 | 200 | 604 | 1103 | 123.3 | 99082698 |
| GT-U+ 300 PN10 | 10 | 300 | 654 | 1286 | 148.3 | 99082699 |
| GT-U+ 500 PN10 | 10 | 500 | 754 | 1561 | 195.5 | 99082700 |
| GT-U+ 750 PN10 | 10 | 750 | 756 | 1834 | 231 | 99082701 |
| GT-U+ 1000 PN10 | 10 | 1000 | 806 | 2376 | 327.5 | 99082702 |
| GT-U+ 1500 PN10 | 10 | 1500 | 958 | 2435 | 391.5 | 99082703 |
GT-U+ 16 Bar Rated Expansion Vessels
Features:
- Low-carbon sheet steel shell
- Replaceable butyl bladder
- Built-in pressure gauge
- Threaded connection
- WRAS approved
- 50% vessel efficiency
| Product Name | Pressure (bar) | Volume (L) | Diameter (mm) | Height (mm) | Weight (kg) | Product Code |
|---|---|---|---|---|---|---|
| GT-U+ 100 PN16 | 16 | 100 | 454 | 983 | 76.5 | 99082706 |
| GT-U+ 150 PN16 | 16 | 150 | 506 | 1058 | 91.5 | 99082707 |
| GT-U+ 200 PN16 | 16 | 200 | 606 | 1105 | 123.3 | 99082708 |
| GT-U+ 300 PN16 | 16 | 300 | 656 | 1288 | 148.3 | 99082709 |
| GT-U+ 500 PN16 | 16 | 500 | 760 | 1565 | 254.5 | 99082710 |
| GT-U+ 750 PN16 | 16 | 750 | 760 | 1862 | 297.5 | 99082711 |
| GT-U+ 1000 PN16 | 16 | 1000 | 810 | 2367 | 409.5 | 99082712 |
| GT-U+ 1500 PN16 | 16 | 1500 | 962 | 2443 | 498 | 99082713 |
| GT-U+ 2000 PN16 | 16 | 2000 | 1116 | 2511 | 717 | 99082714 |
| GT-U+ 3000 PN16 | 16 | 3000 | 1216 | 2938 | 1055 | 99082715 |
Vessel Installation Guidelines
Install expansion vessels on the coldest part of the system (typically return pipe to heat exchanger) to ensure diaphragm temperature does not exceed 70°C. For systems with flow temperatures exceeding 90°C, an intermediate cooling vessel may be required.
Vessel Sizing Calculation (BS 7074)
Expanded Volume = System Volume × Expansion Coefficient at Max Flow Temperature
Approximation when volume unknown:
- Heating systems: 12 litres per 1 kW thermal input
- Chilled systems: 18 litres per 1 kW thermal input
Minimum Vessel Size = (Expanded Volume ÷ Acceptance Factor) + 10%
Acceptance Factor = (Max Working Pressure – Cold Fill Pressure) ÷ Max Working Pressure (Use absolute pressures: add 1.0 bar atmospheric)
Applications
Low Temperature Heating Water Systems
- Commercial building heating
- Residential heating installations
- District heating substations
Medium Temperature Heating Water Systems
- Industrial process heating
- High-temperature HVAC systems
- Manufacturing facilities
Chilled Water Systems
- Air conditioning systems
- Data centre cooling
- Process cooling applications
Benefits of Closed Pressurisation Systems
Versus Traditional Open Systems:
- Dissolved air eliminated, preventing corrosion
- No rooftop tanks required
- Reduced evaporation water loss
- Higher flow temperatures achievable
- Greater temperature drops possible
- Smaller pumps and pipes required
- Lower installation costs
- Reduced maintenance requirements
- Extended system life
Genuine Grundfos Accessories & Parts
Complete your pressurisation installation with genuine Grundfos accessories including CIM communication cards (BACnet/Modbus), high water level sensors, replacement bladders for GT-U+ vessels, pressure gauges, safety valves, and connection fittings. We stock components for complete system solutions.
Select Grundfos Pumps
Browse our complete inventory of Grundfos PHT pressurisation units and GT expansion vessels. As Grundfos Pump Suppliers in Dubai, we provide competitive pricing, technical consultation, and prompt delivery across Dubai, Sharjah, Abu Dhabi, Ajman, and all UAE locations.
Contact us for:
- PHT model selection based on system volume and pressure
- Expansion vessel sizing calculations (BS 7074)
- Wall mounted vs floor standing recommendations
- Single vs twin pump configurations
- Glycol system requirements (V-Series)
- BACnet/Modbus integration support
- Competitive quotations
- Delivery schedules
Complete System Pressure Management
The Grundfos pressurisation range delivers comprehensive solutions for maintaining sealed system integrity. From compact Mini Monopress units for residential applications to sophisticated PHT A V-Series with automatic glycol mixing for chilled water systems, combined with GT expansion vessels rated from 6 to 16 bar, Grundfos provides the reliability, efficiency, and advanced control that modern HVAC installations demand.