Key Highlights

  • Yet the shares, at 7,135p on 13 August, sat mid-way through a 52-week range of 6,300p to 7,960p.
  • Spirax's 2026 Half Year Results, published on 11 August 2026 for the six months to 30 June, showed Revenue of £863.8m, up 5% on both a reported and organic basis from £822.2m a year earlier.
  • Adjusted operating profit rose 8% to £171.1m (6% organic), taking the adjusted Margin to 19.8%, 50 basis points higher on a reported basis.
  • Adjusted profit before tax climbed 9% to £152.3m and adjusted Basic Earnings Per Share reached 150.0p, also up 9%.
  • Statutory operating profit jumped 44% to £154.2m and basic EPS rose 56% to 132.2p, flattered by restructuring charges in the comparative period.

Spirax Group plc (LSE:SPX) has spent two years proving that a steam-engineering specialist can grow faster than the factories it serves. On 11 August 2026 the FTSE 100 company reported half-year organic revenue growth of 5% against global industrial production of 1.5% excluding China, lifted adjusted operating profit by 8% and reaffirmed full-year guidance. Yet the shares, at 7,135p on 13 August, sat mid-way through a 52-week range of 6,300p to 7,960p.

The question for the second half is whether Spirax can convert a record biopharma order book, double-digit semiconductor Demand and a completed £40m cost-savings programme into the margin expansion it has promised, while managing a sharp dip in cash conversion and continued softness in China.

Half-year results: organic growth ahead of markets, guidance reiterated

Spirax's 2026 Half Year Results, published on 11 August 2026 for the six months to 30 June, showed revenue of £863.8m, up 5% on both a reported and organic basis from £822.2m a year earlier. Adjusted operating profit rose 8% to £171.1m (6% organic), taking the adjusted margin to 19.8%, 50 basis points higher on a reported basis. Adjusted profit before tax climbed 9% to £152.3m and adjusted basic earnings per share reached 150.0p, also up 9%.

Statutory operating profit jumped 44% to £154.2m and basic EPS rose 56% to 132.2p, flattered by restructuring charges in the comparative period. The board declared an Interim Dividend of 50.4p, a 3% rise, payable on 13 November 2026.

Group Chief Executive Nimesh Patel said: "Continuing momentum in end markets such as Semicon and Biopharm as well as strong orderbooks, underpin our expectations for second half revenue and profit growth and we are reiterating our full year guidance."

Two details tempered the tone. Adjusted cash conversion fell to 54% from 61%, which the company attributed to planned inventory builds to guard against supply-chain disruption linked to conflict in the Middle East, plus higher receivables from strong Electric Thermal Solutions sales. Corporate costs are also guided higher than 2025 as the group invests in digital and services capabilities.

What Spirax does

Headquartered in Cheltenham, Spirax Group (LSE:SPX), formerly Spirax-Sarco Engineering, employs around 10,000 people in roughly 70 countries and serves more than 100,000 customers, according to its 2025 full-year results. Its three divisions share a direct-sales model in which engineers visit plants to specify, install and maintain equipment, generating a high proportion of recurring maintenance and repair revenue.

Steam Thermal Solutions (STS), the original business, supplies steam-system components, controls and services to food, pharmaceutical, chemical and other process industries. Electric Thermal Solutions (ETS) provides electric process, trace and equipment heating, with semiconductor manufacturers accounting for 13% of divisional sales in 2025. Watson-Marlow Fluid Technology Solutions (WMFTS) makes peristaltic pumps and single-use fluid-path components for biopharmaceutical manufacturers. The group also markets electrification and heat-pump products for industrial decarbonisation, an addressable market it puts at around £7bn a year.

Financial performance: the 2025 base and the 2026 first half

For the year to 31 December 2025, published on 10 March 2026, Spirax reported revenue of £1,702.9m, up 2% reported and 5% organically after a 3% currency headwind. Adjusted operating profit was £339.9m at a 20.0% margin. Statutory operating profit fell 13% to £265.4m after £39.9m of restructuring charges, which consolidated the STS EMEA footprint from 19 operating companies to 10 and separated the ETS Heat Trace business. Adjusted basic EPS rose 3% to 296.3p and the total dividend increased 3% to 170.0p, a 58th consecutive annual rise. Net Debt closed 2025 at £564.7m, or 1.5 times EBITDA, with adjusted free Cash Flow up 15% to £199.0m.

The 2026 first half showed divergent divisional trends. STS revenue of £419.8m grew just 1% organically and adjusted operating profit fell 6% to £92.3m, with the margin down 170 basis points to 22.0% on shipment phasing and first-half-weighted hiring of sales and technical staff. ETS revenue of £232.9m rose 11% organically and profit jumped 27% to £40.0m, lifting its margin to 17.2%. WMFTS revenue rose 7% organically to £211.1m with profit up 11% to £58.0m and a 27.5% margin. Net debt at 30 June 2026 was £618.2m, or 1.6 times EBITDA, down from £658.0m a year earlier.

What could drive the stock next?

The most immediate catalyst is delivery against the second-half guidance set out in August. Management expects high-single-digit sales growth in both ETS and WMFTS in the second half and an STS full-year margin broadly in line with 2025, which implies a marked recovery from the 22.0% reported for the first half. A fourth-quarter trading update or the full-year results in March 2027 will show whether that has materialised.

The biopharma cycle is a second lever. WMFTS orders in the second quarter of 2026 were the highest of any quarter since the 2021 Pandemic peak and above pre-COVID levels, with intake running ahead of sales. Semiconductor Capital spending, which drove double-digit growth in ETS equipment heating, and a growing order book for large customised heaters provide a third source of momentum. Further out, the CONNECT IoT platform launching in 2026 and the full £40m of annualised restructuring savings, only around half of which fell into 2025, should support margins.

Risks investors should watch

China remains the most visible drag. Sales there fell 1% organically in the first half after a 6% decline a year earlier, with large projects still weak. STS, the largest division, grew only 1% organically and its margin decline needs to reverse for group guidance to hold.

Cash generation is a second concern. First-half conversion of 54% was 700 basis points lower than a year earlier, and management's expectation of a full-year figure similar to 2025 relies on unwinding precautionary inventory. Net debt of £618.2m sits above the group's 1.0 to 1.5 times Leverage target on a half-year basis.

Externally, the company describes the macroeconomic impact of trade tariffs as uncertain, "compounded by the ongoing variation in rates and administrative complexity." Currency reduced adjusted operating profit by 2% in the first half, and higher corporate costs will weigh on operating leverage.

Outlook

Spirax enters the second half with reaffirmed guidance for mid-single-digit organic revenue growth and organic margin progress, supported by strong order books in biopharma and semiconductors. The key evidence points will be the STS margin recovery, the normalisation of Working Capital and any sign that China is stabilising. With the shares sitting mid-range as at mid-August, investors will look to the next trading update and the March 2027 full-year results for confirmation that the growth-ahead-of-markets model is delivering the profit and cash conversion the company has promised.