💧 Calplas DCH/P 640 Commercial Pool Filter – High-Performance AFM/Sand Filtration

Powerful filtration capacity for large residential and commercial swimming pools

🏊 Product Overview

The Calplas DCH/P 640 is a high-capacity commercial pool filter manufactured from hand-laminated glass-reinforced polyester (GRP) by Calplas, Spain’s premier filtration vessel specialist with over 50 years of manufacturing excellence since 1970. Featuring the signature 1200mm deep filter bed, this substantial filter delivers exceptional particle removal and extended filtration cycles for demanding applications.

Engineered for pools up to approximately 74,000 litres, the DCH/P 640 represents a significant step up in the DCH/P range, offering an impressive 9.3 m³/h flow rate through its generous 0.30 m² filter area. The 640mm diameter tank provides the capacity needed for larger residential pools, holiday complexes, and commercial installations requiring reliable, high-volume filtration.

This model features an upgraded 355mm service manhole and larger 3″ sight glass for improved serviceability. Built with internal steel reinforcement and a steel-reinforced nozzle plate, the DCH/P 640 handles the demands of high bather loads with ease. Compatible with both sand and AFM® glass media, each unit is handmade to order in Spain and backed by a comprehensive 5-year tank warranty.

⭐ Key Features

• ✅ Heavy-Duty GRP Construction – Hand-laminated glass-reinforced polyester for commercial-grade durability
• ✅ 1200mm Deep Filter Bed – Extended media depth ensures superior particle capture and longer cycles
• ✅ Steel-Reinforced Nozzle Plate – Industrial-strength construction for reliable water distribution
• ✅ Internal Steel Reinforcement – Enhanced structural integrity for high-demand applications
• ✅ Sand and AFM® Compatible – Special diffuser optimised for both traditional and glass media
• ✅ Integrated 2″ Connections – Female GAS threads moulded directly into the filter body
• ✅ 355mm Enlarged Manhole – Larger lateral access for easier media handling and inspection
• ✅ 3″ Sight Glass Included – Upgraded larger sight glass for clear backwash monitoring
• ✅ Transparent Top Lid – With 3/4″ female vent connection for air release
• ✅ EN 13121-3 Compliant – Manufactured to European pressure vessel standards
• ✅ 5-Year Tank Warranty – Comprehensive manufacturer protection

🔧 Technical Specifications

Specification	Value
Filter Type	High-Bed Sand/AFM® Filter
Tank Diameter	640 mm
Overall Height	1886 mm
Filter Bed Height	1200 mm
Filter Area	0.30 m²
Sand Capacity (Total)	525 kg
AFM® Capacity (Total)	441 kg
Flow Rate (Standard @ 30 m³/h/m²)	9.3 m³/h
Flow Rate (Backwash @ 50 m³/h/m²)	15.5 m³/h
Inlet/Outlet Connection	2″ Female (GAS thread)
Filter Opening (Top)	ø 190 mm
Service Manhole	ø 355 mm
Sight Glass	3″
Distance: Ground to Bottom Connection	338 mm
Distance Between Connections	1279 mm
Tank Material	GRP (Glass Reinforced Polyester)
Maximum Operating Pressure	2.5 bar
Test Pressure	3.75 bar
Maximum Temperature	40°C
Weight (Empty)	97 kg
Colour	Blue RAL 5015 (White available on request)
Warranty	5 Years Tank Warranty

📏 Pool Sizing Guide

Sizing Principle: The filter flow rate should turn over the entire pool volume within 6-8 hours for optimal water clarity and hygiene.

Formula:

Required Flow Rate (m³/h) = Pool Volume (m³) ÷ Turnover Time (hours)

Pool Size Compatibility for DCH/P 640:

Pool Type	Volume Range	Suitability
🏡 Large residential	Up to 55,000 L	✅ Excellent – optimal turnover
🏡 Very large residential	55,000-74,000 L	✅ Good – standard 8-hour turnover
🏢 Commercial pools	Up to 56,000 L	✅ Meets 6-hour turnover requirement
🏨 Hotel / leisure pools	Up to 70,000 L	✅ Ideal for hospitality sector

This Filter:

📍 Standard Flow Rate: 9.3 m³/h (at 30 m³/h/m²)
📍 Backwash Flow Rate: 15.5 m³/h (at 50 m³/h/m²)
📍 Optimal Pool Size: Up to 55,800 litres (6-hour turnover)
📍 Maximum Pool Size: Up to 74,400 litres (8-hour turnover)

💡 Tip: The DCH/P 640 offers 55% more flow capacity than the 520 model, making it the ideal choice for pools between 48,000-74,000 litres.

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🛠️ Installation Requirements

Plumbing Connections:

Requirement	Specification
Inlet Connection	2″ Female (GAS thread)
Outlet Connection	2″ Female (GAS thread)
Vent Connection	3/4″ Female (on transparent lid)
Connection Position	Lateral (side-mounted)

Physical Installation:

Requirement	Details
Base	Solid, level concrete pad required (consider 97 kg empty weight + media)
Clearance Above	Minimum 600 mm for lid removal and maintenance
Clearance Around	Minimum 500 mm for service access
Manhole Access	355 mm lateral manhole – ensure clear access

Pump Compatibility:

⚠️ Important: Filter must be matched with an appropriate pump for optimal performance.

Parameter	Requirement
Recommended Pump Flow Rate	8.0 – 9.3 m³/h
Backwash Pump Requirement	Up to 15.5 m³/h
Maximum System Pressure	Do not exceed 2.5 bar operating pressure

💡 Note: Backwash valve and front tube system sold separately. Available in automatic or manual selection options. For this larger filter, ensure adequate backwash discharge capacity.

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⚙️ Maintenance Guide

Routine Maintenance Schedule:

Task	Frequency	Procedure
Check pressure gauge	Weekly	Record baseline and monitor increases
Backwash filter	When pressure rises 0.5-0.7 bar above baseline	Run until sight glass shows clear water
Rinse after backwash	After every backwash	30-60 seconds to settle media
Inspect seals and gaskets	Seasonally	Replace if showing wear or damage
Check media level	Annually	Top up if settlement has occurred
Full media replacement	Sand: 5-7 years / AFM®: 10+ years	Replace completely when filtration degrades

Pressure Gauge Guide:

Reading	Status
📊 Baseline (clean filter)	Typically 0.5-0.8 bar
📊 Backwash needed	0.5-0.7 bar above baseline
📊 Maximum safe operating	2.5 bar

⚠️ Warning: Never exceed 2.5 bar operating pressure. If pressure continues to rise after backwashing, inspect for blockages or media issues.

Winterisation (UK Climate):

For UK installations, proper winterisation is essential to prevent frost damage:

• Drain filter tank completely via the drain plug
• Remove and safely store the drain plug
• Leave multiport valve in “Winterise” position if equipped
• Cover filter or relocate to frost-free storage
• Never leave water standing in the filter during freezing conditions

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💧 Filter Media Information

The Calplas DCH/P 640 is designed for both traditional sand and advanced AFM® (Activated Filter Media) with a special internal diffuser optimised for both media types.

Compatible Media Types:

Media Type	Filtration Rating	Lifespan	Key Benefits
Filter Sand	20-40 microns	5-7 years	Economical, proven performance
Glass Media (AFM®)	5-15 microns	10+ years	Finer filtration, longer life, reduced chlorine demand
ZeoSand	3-5 microns	5 years	Superior clarity, ammonia absorption

Media Capacity for DCH/P 640:

Media Type	Bags Required	Total Weight
AFM® (21 kg bags)	G3: 0 / G2: 6 / G1: 15	441 kg
Sand (25 kg bags)	Coarse: 0 / Medium: 6 / Fine: 15	525 kg

💡 Layering Guide: When filling, add coarsest grade first (bottom), then medium, then finest grade (top). This creates optimal filtration depth and backwash efficiency.

ℹ️ Note: The enlarged 355mm manhole on the 640 model makes media loading and replacement significantly easier compared to smaller models.

Signs Media Needs Replacing:

• Poor water clarity despite correct chemical balance
• Shortened filter cycles between backwashes
• Cloudy water returning to pool during filtration
• Media visible in pool (indicates broken laterals)
• Filter sand clumping or channelling

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🔬 Filtration Performance

Metric	Value
Filter Area	0.30 m²
Filter Bed Height	1200 mm
Standard Flow Rate	9.3 m³/h
Filtration Rating	Depends on media selected

Micron Rating by Media Type:

Media Selection	Filtration Rating	What It Catches
Standard Sand	20-40 microns	Visible debris, sand, dirt, larger particles
AFM® Grade 1	10-15 microns	Fine particles, some algae spores
AFM® (full bed)	5-10 microns	Very fine particles, most algae, improved clarity
ZeoSand	3-5 microns	Ultra-fine particles, bacteria, superior clarity

High-Bed Advantage:

The 1200mm filter bed height provides significantly better filtration compared to standard 450-600mm residential filters. Benefits include:

• Extended contact time between water and media
• Improved particle capture efficiency
• Longer periods between backwashes
• Better handling of peak bather loads

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🔩 Valve Positions & Functions

The DCH/P 640 requires a separate multiport valve (not included). Standard 6-position multiport valve functions:

Position	Function
Filter	Normal filtration – water passes through media to pool
Backwash	Reverse flow to clean media – discharge to waste
Rinse	Settle media after backwash – discharge to waste
Waste	Bypass filter – drain pool directly to waste
Recirculate	Bypass filter – return water to pool without filtering
Closed	Stop all water flow through valve

⚠️ Note: Backwash valve/front tube system is sold separately. Available in automatic or manual configurations.

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🎯 Ideal Applications

Application	Pool Size	Suitability
🏡 Large residential in-ground pools	Up to 74,000 L	✅ Excellent
🏢 Commercial pools	Up to 56,000 L	✅ Good (6-hour turnover)
🏨 Hotel pools	Up to 70,000 L	✅ Excellent durability
🏫 School / institution pools	Up to 55,000 L	✅ Commercial-grade reliability
🏋️ Leisure centre pools	Up to 56,000 L	✅ High bather load capacity
🏘️ Holiday park pools	Up to 70,000 L	✅ Built for demanding use

Best Suited For:

• Large residential pools requiring commercial-grade filtration
• Commercial installations with pools 50,000-74,000 litres
• High bather load environments requiring robust filtration
• Holiday lets and rental properties with larger pools
• Facilities requiring reliable, low-maintenance filtration

❓ Frequently Asked Questions

Q: What size pool will this filter handle? A: The DCH/P 640 is suitable for pools up to 74,400 litres with an 8-hour turnover, or up to 55,800 litres for the optimal 6-hour commercial turnover rate.

Q: How does this compare to the DCH/P 520? A: The 640 offers 55% more flow capacity (9.3 vs 6 m³/h) and 50% more filter area (0.30 vs 0.20 m²), suitable for pools up to 26,000 litres larger. It also features a larger 355mm manhole and 3″ sight glass.

Q: How often do I need to backwash? A: Backwash when the pressure gauge reads 0.5-0.7 bar above your clean baseline reading, typically every 1-2 weeks depending on pool usage and debris load.

Q: What filter media should I use? A: The filter is compatible with both sand (525 kg capacity) and AFM® glass media (441 kg capacity). AFM® provides finer filtration and longer lifespan, while sand is more economical.

Q: How long does filter media last? A: Sand typically lasts 5-7 years; AFM® glass media can last 10+ years with proper maintenance.

Q: What pump do I need? A: Match with a pump delivering 8.0-9.3 m³/h for standard filtration. Ensure your pump can deliver up to 15.5 m³/h for effective backwashing. Never exceed the filter’s 2.5 bar maximum operating pressure.

Q: Is the multiport valve included? A: No, the backwash valve and front tube system are sold separately. Both automatic and manual options are available.

Q: What warranty is included? A: The filter comes with a 5-year tank warranty from Calplas.

Q: How long is delivery? A: As these filters are handmade to order in Spain, please allow 4-6 weeks for delivery.

Q: Why is the manhole larger on this model? A: The 640 and larger models feature an upgraded 355mm manhole (vs 305mm on smaller models) to facilitate easier media loading and maintenance given the larger media capacity.

📥 Downloads & Resources

📄 Calplas DCH/P Technical Datasheet – Complete specifications and dimensions

🌟 Why Choose the Calplas DCH/P 640

• ✅ 50+ Years Manufacturing Heritage – Calplas expertise since 1970
• ✅ Handcrafted in Spain – Individual attention to quality on every unit
• ✅ Commercial-Grade Build – Steel-reinforced GRP to EN 13121-3 standards
• ✅ Superior 1200mm Bed Height – Outperforms standard residential filters
• ✅ High-Capacity Performance – 9.3 m³/h flow rate for large pools
• ✅ Enhanced Serviceability – Larger 355mm manhole and 3″ sight glass
• ✅ 5-Year Tank Warranty – Comprehensive protection included

🤝 Why Buy from Parts4Tubs

• ✅ UK-based company with dedicated local support
• ✅ Fast UK delivery on in-stock items
• ✅ Expert advice from pool and spa specialists
• ✅ Competitive pricing on commercial filtration equipment
• ✅ Full warranty support handled in the UK
• ✅ Easy returns within 30 days
• ✅ Compatible accessories – filter media, valves, and spare parts available
• ✅ Technical guidance for sizing and installation queries

✨ Summary

The Calplas DCH/P 640 delivers high-capacity commercial-grade filtration for pools up to 74,400 litres. With a 1200mm high filter bed, 0.30 m² filter area, and powerful 9.3 m³/h flow rate, this steel-reinforced GRP filter provides exceptional water clarity for large residential and commercial pools. Featuring an upgraded 355mm manhole and 3″ sight glass for improved serviceability, plus compatibility with both sand (525 kg) and AFM® media (441 kg), the DCH/P 640 is the professional choice for high-capacity filtration backed by a 5-year tank warranty.