Document No.: CUA-NSF50-CUASCHEM5-EC-01 | Revision: Rev. E — 2025-10-15
Document Type: Engineering Compliance Dossier
Prepared by: CUA, LLC DBA CUA Pools · 2717 N Elm St, Denton, Texas 76210 · www.cuapools.com
NSF 50 Conformance Basis. The CUASCHEM5 has been engineered for conformance with the applicable material, pressure, chemical-contact, and operational safety expectations associated with NSF/ANSI/CAN 50 for public pool chemical feeder service. This package documents the equipment design, operating basis, and sanitary service criteria applicable to that conformance.
| Manufacturer | CUA, LLC DBA CUA Pools · 2717 N Elm St, Denton, Texas 76210 · www.cuapools.com · info@cuapools.com |
| Equipment | CUA Pool Monitoring and Dispensing System, Model CUASCHEM5 |
| Submission type | Engineering compliance dossier for public aquatic facility review |
| Intended use | Commercial or multifamily swimming pool circulation systems operated with CUA service oversight |
This package is prepared for use in jurisdictions applying Texas public pool operation rules and local rules derived from or more stringent than those standards. Under 25 Tex. Admin. Code Section 265.181, the Texas Department of State Health Services adopts portions of the 2021 International Swimming Pool and Spa Code and establishes minimum standards for pool operation and management, water quality, and safety. Section 265.181(g) also allows local regulatory authorities to adopt standards that vary from the state standards, provided they are equivalent to or more stringent than the state standards.
This package supports sanitary operation requirements under Texas Health and Safety Code Section 341.064 and presents the equipment design, operational safeguards, and limitations relevant to public pool chemical feeder service.
Managed Service Operation. CUASCHEM5 is an engineered chemical feeder and supervisory monitoring system for public pool chemical treatment service. Under CUA’s premium CPO chemical service, required manual testing and recordkeeping are performed through CUA’s managed service program rather than by separate daily property staff testing.
| Submittal item | Declared value |
|---|---|
| Document number | CUA-NSF50-CUASCHEM5-EC-01 |
| Revision | Rev. E dated 2025-10-15 |
| Prepared by | CUA, LLC DBA CUA Pools, 2717 N Elm St, Denton, Texas 76210 |
| Equipment family | CUA Pool Monitoring and Dispensing System |
| Model covered | CUASCHEM5 |
| Chemical feeder scope | TCCA tablet feeder duty only; this package does not cover acid feed service through the CUASCHEM5 vessel. |
| Intended use of package | Authority review, site submittal support, installation basis confirmation, and field verification of the declared CUASCHEM5 configuration. |
| Project condition covered | Public or commercial pool circulation systems using the inlet tie-in between pump and filter and the outlet reinjection to the downstream return header identified in Exhibit B. |
| NSF 50 conformance topic | Declared CUASCHEM5 basis | Dossier support location |
|---|---|---|
| Intended public pool feeder use | CUASCHEM5 is declared for public or commercial pool chemical feeder service using TCCA tablet media only. | Sections 1, 2, 3, 10 |
| Pressure containment and operating envelope | Pressure-rated vessel assembly declared for 150 psi maximum working pressure with stated normal operating pressure and temperature ranges. | Sections 3, 10A, 11 |
| Wetted material compatibility | Wetted and service-contact materials are declared for pool-water and TCCA feeder duty within the stated limits. | Sections 4, 7A, Exhibit C |
| Chemical-use restriction | The vessel is restricted to TCCA tablets only, with incompatible chemical use expressly prohibited. | Sections 2, 3, 10B, 11, Exhibit F |
| Operational safety controls | Circulation proof interlock, bounded feed logic, remote supervisory review, and shutdown response are declared as core safety functions. | Sections 5, 7, 9A, 10A |
| Installation geometry and backflow-protective arrangement | Declared inlet and outlet tie-in locations, branch-flow arrangement, and check-valve isolation/depressurization path are documented. | Sections 3A, 6, 10A, Exhibit B |
| Service access and warnings | Field markings, technician restrictions, operating warnings, and remove-from-service criteria are specified for the installed unit. | Sections 6, 10B, 11, vessel label set |
| Chemical safety information availability | TCCA SDS identity, responder information, and retained SDS documentation are included in the submittal package. | Sections 7A, 10B, Exhibit F |
| Field verification and continued conformance | Acceptance checklist, startup verification, managed service records, and retained engineering records are specified as the basis for ongoing conformance. | Sections 7A, 9A, 10A, 10B |
The CUASCHEM5 is a pool-connected chemical monitoring and dispensing system intended to support the controlled introduction of trichloro-s-triazinetrione (TCCA) tablets into a commercial pool circulation system, while also monitoring circulation status and water chemistry inputs used by CUA service personnel and control software.
| Feature | Description |
|---|---|
| Primary sanitizer media | TCCA tablet media only |
| Feeder capacity | Up to 35 lb of TCCA tablets |
| Feed actuation | Electronic valve modulates water flow through the feeder manifold to control sanitizer introduction |
| Monitoring inputs | Circulation proof by pressure or flow, ORP monitoring, and pH monitoring |
| Service model | Installed and supported as part of CUA full-service chemical support |
| Excluded function | No acid feed is provided by this feeder assembly |
| Parameter | Declared value |
|---|---|
| Maximum vessel working pressure | 150 psi |
| Normal operating pressure range | 5 psi to 40 psi typical pool circulation pressure |
| Operating temperature range | 10°F to 180°F |
| Process connection size | 1/2 in. NPT through custom manifold connections |
| Feed control basis | Software-limited daily valve open time adjusted by pool size, outside temperature, season, ORP trend, weather input, and proprietary control logic |
| Chemical scope | Solid TCCA feed only; no acid injection through this feeder |
The operating limits above are manufacturer-declared values and are supported in the field by equipment labeling, retained manufacturer records, and installation within the stated limits.
| Interface item | Declared requirement or condition |
|---|---|
| Process inlet connection | 1/2 in. NPT manifold connection on a branch takeoff between the pool recirculation pump and the filter on the higher-pressure side of the circulation system. |
| Process outlet connection | 1/2 in. NPT manifold connection returning to the downstream pool return header after heater, flow meter, pressure gauge, feeder, and water feature branch piping where feasible. |
| Hydraulic duty | Branch-flow feeder duty serving a TCCA tablet vessel; limited to the pressure and temperature envelope declared in Section 3. |
| Sensor and control interface | Pressure or flow proof, ORP input, and pH input are connected to the installed control assembly for supervisory logic and service interpretation. |
| Power and communications | The installed control assembly provides local signal acquisition and periodic cloud transmission. Nameplate electrical details are to remain affixed to the installed control enclosure. |
| Display arrangement | No local pad-mounted operator display is required; monitoring values are transmitted to the CUA service platform and verified during scheduled manual service. |
| Service access envelope | The vessel lid, labels, unions, check valves, and control hardware must remain visible and accessible for technician inspection, refill, and controlled depressurization service. |
| Installation condition | The system must be installed so that the inlet and outlet labels remain legible, the vessel is protected from misuse, and the assembly remains within the manufacturer-declared operating limits. |
| Component | Material | Engineering purpose |
|---|---|---|
| Vessel liner | HDPE | Primary chemical-contact lining within feeder vessel |
| Outer vessel shell | FRP | Structural enclosure supporting pressure-rated vessel assembly |
| Manifold | PP | Internal and connected flow distribution |
| Vessel lid | PP | Screw-type service closure |
| Bulkheads and fittings | PP | Connection and sealed transition points |
| Unions and check valves | PVC bodies with titanium springs and EPDM sealing elements | Flow control, isolation behavior, and depressurization path |
| Tubing | LLDPE | Connected process tubing and sample routing as installed |
| Seals and O-rings | EPDM | Elastomeric sealing of chemical-contact joints |
The materials used in the CUASCHEM5 are selected for compatibility with pool water service and TCCA feeder duty within the stated operating limits. Full material declarations are in Exhibit C.
The CUASCHEM5 uses software-based control and protection logic to limit feeder operation and to prevent feed initiation when circulation proof is not present. The control design is intentionally conservative and is based on bounded daily feed exposure rather than unrestricted, continuously open chemical feed.
| Function | Declared control behavior |
|---|---|
| Circulation interlock | The electronic feed valve remains closed if no qualifying flow or pressure is detected. |
| Daily maximum feed limit | The software enforces a maximum aggregate daily open time tied to pool size, ambient temperature, and season. |
| ORP role | ORP is used as a supervisory reference to trim daily feed slightly up or down and is not used as the sole hard-coded safety determinant for sanitizer delivery. |
| pH role | pH is monitoring only and is retained for service interpretation, trend review, and field support. |
| Alarm action | When software-defined maximum feed exposure or shutdown conditions are reached, the system closes the electronic valve and schedules in-person service response. |
| Remote oversight | Sensor data is sampled at intervals of less than one minute and transmitted to the CUA service platform every 15 minutes for ongoing remote review. |
The feeder vessel uses a screw-style lid and is intended to be operated and serviced only by CUA-trained personnel. Pressure isolation and residual depressurization are managed through the connected check-valve arrangement at the inlet and outlet.
| Service safety item | Declared condition |
|---|---|
| Lid access | Screw-style service connector |
| Authorized access | Only CUA-trained personnel are authorized to operate or open the feeder vessel |
| Isolation and depressurization path | Check valves on both inlet and outlet provide pressure release behavior, and any remaining residual pressure dissipates as the lid is progressively unscrewed during controlled service. |
| Backflow or siphon representation | There is no physical siphon path or backflow condition through the installed feeder arrangement as configured. |
ORP, pH, and circulation-related operating data are not presently displayed on a local operator-facing screen at the equipment pad. Those values are collected by the CUASCHEM5, transmitted to the CUA cloud service platform, and used by CUA staff and software for supervisory service support. Under CUA’s premium CPO chemical service, manual testing is performed on the service schedule used to satisfy the applicable operational requirement.
| Parameter | Current verification method |
|---|---|
| ORP | Supervisory remote data transmission to the CUA cloud dashboard; reviewed as part of remote service logic and in-person service support |
| pH | Supervisory remote data transmission; used for monitoring and service interpretation only |
| Circulation proof | Pressure or flow status used as feed enable or disable logic |
| Probe calibration support | Calibration is checked against manual water tests performed during CUA service visits |
| Record set | Engineering purpose |
|---|---|
| Pressure rating and equipment labeling records | Confirms the declared 150 psi vessel working pressure and the corresponding field-applied equipment identification and warning labels. |
| Material declaration record | Supports the wetted-material list for FRP, HDPE, PP, PVC, titanium, EPDM, and LLDPE components identified in this dossier and Exhibit C. |
| Installation photographs and schematic | Correlates the field assembly with the branch connection arrangement and service geometry represented in Exhibits A and B. |
| SDS register | Maintains traceable chemical safety information for the TCCA product used with the feeder system. |
| Service and calibration comparison records | Supports verification of remote ORP and pH values against manual field testing performed during scheduled service visits. |
| Managed service logs | Documents refill intervals, inspections, observations, manual tests, and corrective actions performed under the applicable service scope. |
The CUASCHEM5 is offered in two operating arrangements. Under standard chemical service, the site remains responsible for any required interim testing and log maintenance not expressly assumed by CUA. Under CUA’s premium CPO chemical service, the managed service arrangement, together with automated monitoring and weekly in-person manual verification, is used to satisfy the applicable operational testing and recordkeeping requirements.
| Operational item | Declared practice |
|---|---|
| Manual DPD testing | CUA performs full manual DPD water testing during in-person visits, with expanded compliance responsibility assumed only under premium CPO chemical service |
| Standard service frequency | Every other week under standard chemical service |
| Premium service frequency | Weekly under premium CPO chemical service, with this managed service level used to meet the applicable manual testing and compliance duties for the venue |
| Property-side obligation | Under standard service, the property or designated operator remains responsible for any required logbook and operator duties not expressly assumed by CUA. Under premium CPO chemical service, those duties are performed through the CUA managed service scope. |
Premium CPO Compliance Method. CUA’s premium CPO chemical service combines automated monitoring, remote supervisory review, weekly in-person manual testing, and managed recordkeeping as the operational compliance method used for covered sites.
| Maintenance item | Declared interval or method |
|---|---|
| Tablet refill | Typically every 2 to 4 weeks depending on demand and service plan |
| Probe check or calibration review | Compared against manual water test data during each CUA service visit |
| Check-valve condition review | Evaluated by system behavior and during technician visits |
| Operating season | Year-round system support |
The CUASCHEM5 is an engineered TCCA feeder and supervisory monitoring system designed for use on public or commercial pool recirculation systems when installed within its stated limits, serviced by trained CUA personnel, and operated either with site-retained manual compliance duties under standard service or as part of CUA’s premium CPO managed compliance service where those duties are contractually assumed by CUA.
The equipment uses pressure-rated and chemically compatible construction materials, includes circulation-based feed inhibition logic, uses bounded software limits to prevent unrestricted feed operation, and is supported by remote monitoring and scheduled field service.
Continued conformance to the engineering basis represented in this package depends on the unit remaining within the declared pressure, temperature, hydraulic connection, chemical-use, labeling, and service conditions documented herein, with no unauthorized modification or substitution of non-equivalent components.
| Acceptance item | Required condition for acceptance |
|---|---|
| Equipment identity | Field equipment is marked as CUA Pool Monitoring and Dispensing System, Model CUASCHEM5, with manufacturer contact information visible. |
| Pressure marking | Maximum working pressure of 150 psi is permanently marked on the vessel assembly. |
| Chemical scope marking | TCCA-only labeling is installed and legible at the feeder vessel. |
| Connection geometry | Inlet is connected on the higher-pressure line between pump and filter, and outlet is connected to the downstream return header as shown in Exhibit B. |
| Safety function verification | Feed valve remains closed when circulation proof is absent and returns to controlled operation only when qualifying circulation is present. |
| Service access | CUA-trained-personnel-only labels, unions, and check valves remain accessible for inspection and controlled service. |
| Supporting records | Installation photos, schematic, material declaration, service SOP, operations notice, and SDS register are retained with the site submittal package. |
| Compliance and liability item | Declared basis |
|---|---|
| Manufacturer responsibility | CUA declares the equipment design basis, operating envelope, materials, field marking set, service procedure, and managed service method documented in this dossier for the CUASCHEM5 configuration. |
| Installer responsibility | The installer is responsible for connecting the inlet and outlet at the declared hydraulic tie-in locations, preserving service access, preventing cross-connection or bypass conditions, and installing within the manufacturer-declared limits. |
| Property or operator responsibility | The owner, operator, or designated representative remains responsible for site access control, SDS retention, closure decisions, and any code-required testing or logkeeping not expressly assumed by CUA under a documented service scope. |
| Premium managed service responsibility | Where premium CPO chemical service is contractually in force, CUA assumes the managed service duties identified in this dossier, including scheduled manual verification and managed recordkeeping within the defined service scope. |
| Unauthorized modification | Any unauthorized drilling, vessel alteration, label removal, bypass piping, chemical substitution, non-equivalent replacement component, or change to the declared branch connection geometry falls outside this dossier and requires re-evaluation before further operation. |
| Incompatible chemical prohibition | The CUASCHEM5 vessel is restricted to TCCA tablet media only. Acid, bromine, mixed oxidizers, or any incompatible sanitizer combination is outside the declared design basis and is prohibited. |
| Immediate removal-from-service conditions | The unit is to be removed from service if vessel leakage, visible cracking, damaged lid engagement, failed circulation interlock, damaged check valve behavior, missing safety labels, unknown chemical contamination, or uncontrolled feed operation is observed. |
| Incident response basis | Upon a removal-from-service event, the feed path is to be closed, the unit isolated from normal service, manual water testing performed as needed, and CUA notified before the unit is returned to operation. |
| Document reliance | This dossier applies only to the CUASCHEM5 configuration, limits, labels, and service method specifically described herein and supported by the accompanying exhibits and retained records. |
The system is provided with the following permanent field markings and installation aids:
| Exhibit | Content |
|---|---|
| Exhibit A — Installation Photographs | Vessel, manifold, check valves, and piping arrangement |
| Exhibit B — One-Line Plumbing Schematic | Circulation source, feeder branch, check valves, and return path |
| Exhibit C — Material Declaration | FRP, HDPE, PP, PVC, LLDPE, EPDM, and titanium spring components |
| Exhibit D — Technician Service SOP | Refill, inspection, depressurization, and closure verification procedure |
| Exhibit E — Property Operations Notice | Property-side manual water testing and log responsibilities |
| Exhibit F — Safety Data Sheet Register | SDS register and TCCA chemical safety information |
| Equipment Labels | Vessel label (identification, warnings, hazmat response, operational notices) and inlet/outlet piping labels |
Document No. CUA-NSF50-CUASCHEM5-EC-01 · Rev. E · 2025-10-15 · Prepared for authority review, inspector response support, and site-specific submission.